The first known inhabitants of what is now the United States are believed to have arrived over a period of several thousand years beginning sometime prior to 15,000–50,000 years ago by crossing Beringia into Alaska. These people are known as the Native Americans or, incorrectly, as "Indians". Solid evidence of these cultures settling in what would become United States territory is dated to around 14,000 years ago. Research has revealed much about the early Native American in North America. Christopher Columbus' men were the first documented settlers from the Old World to land in the territory of what is now the United States when they arrived in Puerto Rico during their second voyage in the year 1493. Juan Ponce de León, who arrived in Florida in 1513, is credited as being the first European to land in what is now the continental United States, although some evidence suggests that John Cabot might have reached what is presently New England in 1498.

The arrival of Europeans began the colonial history of the United States. The Thirteen Colonies, British colonies that would become the original US states, were founded along what is now the country's east coast beginning in 1607. Various other European powers also founded settlements in what would become US territory, both before and later. Due to growing dissatisfaction with British rule, the thirteen British colonies fought the British army in the American Revolutionary War of the 1770s and issued a Declaration of Independence in 1776. In early 1781, the Articles of Confederation and Perpetual Union of the States were established, six months before the end of hostilities in the Revolutionary War. Two years later, Britain officially recognized the sovereignty and independence of the United States in the Treaty of Paris. After the nation split along state lines in 1861, the Civil War—the deadliest war in US history—reunified the country. In the nineteenth century, westward expansion of United States territory began, encouraged by the belief in Manifest Destiny, in which the United States would occupy all of North America east to west, from the Atlantic to the Pacific Oceans. By 1912, with the admission of Arizona to the Union, the US reached that goal. The outlying states of Alaska and Hawaii were both admitted in 1959.

Ratified in 1788, the US Constitution serves as the supreme law in organizing the government; the Supreme Court is responsible for upholding Constitutional law. Many forms of social progress started in the nineteenth century; those advancements have been widely reflected in the Constitution. Slavery was abolished in 1865 by the Thirteenth Amendment to the United States Constitution; the following Fourteenth and Fifteenth Amendments respectively guaranteed citizenship for all persons naturalized within US territory and voting for people of all races. In later decades, civil rights were extended to women and African-Americans, following effective lobbying from social activists. The Nineteenth Amendment prohibited gender discrimination in voting rights; later, the Civil Rights Act of 1964 outlawed racial segregation in public places.

The Progressive Era marked a time of economic growth for the United States, advancing to the Roaring Twenties. However, the Wall Street Crash of 1929 led to the Great Depression, a time of economic downturn and mass unemployment. Consequently, the U.S. government established the New Deal, a series of reform programs that intended to assist those affected by the Depression. The New Deal had varied success. However, once the US entered World War II in December 1941, the economy quickly recovered, so much that the US became a world superpower by the dawn of the Cold War. During the Cold War, the US and the Soviet Union were the world's two superpowers, but with the end of the Cold War and the collapse of the Soviet Union, the United States became the world's only superpower.

Pre-Columbian period

The earliest known inhabitants of what is now the United States are thought to have arrived in Alaska by crossing the Bering land bridge, at least 14,000 – 30,000 years ago. Some of these groups migrated south and east, and over time spread throughout the Americas. These were the ancestors to modern Native Americans in the United States and Alaskan Native peoples, as well as all indigenous peoples of the Americas.

Many indigenous peoples were semi-nomadic tribes of hunter-gatherers; others were sedentary and agricultural civilizations. Many formed new tribes or confederations in response to European colonization. Well-known groups included the Huron, Apache Tribe, Cherokee, Sioux, Delaware, Algonquin, Choctaw, Mohegan, Iroquois (which included the Mohawk nation, Oneida tribe, Seneca nation, Cayuga nation, Onondaga and later the Tuscarora tribe) and Inuit. Though not as technologically advanced as the Mesoamerican civilizations further south, there were extensive pre-Columbian sedentary societies in what is now the US. The Iroquois had a politically advanced and unique social structure that was at the very least inspirational if not directly influential to the later development of the democratic United States government, a departure from the strong monarchies from which the Europeans came.

North America's Moundbuilder Culture

Mound Builder is a general term referring to the original inhabitants who constructed various styles of earthen mounds for burial, residential and ceremonial purposes. These included Archaic, Woodland period (Adena and Hopewell cultures), and Mississippian period Pre-Columbian cultures dating from roughly 3000 BC to the 16th century AD, and living in the Great Lakes region, the Ohio River region, and the Mississippi River region.

Mound builder cultures can be divided into roughly three eras:

Archaic era

Poverty Point in what is now Louisiana is perhaps the most prominent example of early archaic mound builder construction (c. 2500 – 1000 BC). An even earlier example, Watson Brake, dates to approximately 3400 BC and coincides with the emergence of social complexity worldwide.

Woodland period

The Archaic period was followed by the Woodland period (c. 1000 BC). Some well-understood examples would be the Adena culture of Ohio and nearby states and the subsequent Hopewell culture known from Illinois to Ohio and renowned for their geometric earthworks. The Adena and Hopewell were not, however, the only mound building peoples during this time period. There were contemporaneous mound building cultures throughout the Eastern United States.

Mississippian culture

Around 900 – 1450 AD the Mississippian culture developed and spread through the Eastern United States, primarily along the river valleys. The location where the Mississippian culture is first clearly developed is located in Illinois, and is referred to today as Cahokia.

Colonial period

After a period of exploration by people from various European countries, Spanish, Dutch, English, French, Swedish, and Portuguese settlements were established. Christopher Columbus first landed and encountered indigenous peoples, mainly the Arawak natives, on what is now the Bahama Islands. The natives were extremely friendly and were frequently remarked by European observers for their hospitality and belief in sharing. The Arawaks had lived in village communes, and had an advanced agriculture consisting of maize, yams, and cassava. They spun and wove textiles, however they had no work animals for labor. Columbus would later describe his initial encounter in his captain's log,

"They...brought us parrots and balls of cotton and spears and many other things, which they exchanged for the glass beads and hawks' bells.

They willingly traded everything they owned...

They were well-built, with good bodies and handsome features...

They do not bear arms, and do not know them, for I showed them a sword, they took it by the edge and cut themselves out of ignorance.

They have no iron.

Their spears are made of cane....

They would make fine servants....

With fifty men we could subjugate them all and make them do whatever we want."

Columbus was the first European to set foot on what would one day become US territory when he came to Puerto Rico on November 19, 1493, during his second voyage.

In the 16th century, Europeans brought horses, cattle, and hogs to the Americas and, in turn, took back to Europe maize, potatoes, tobacco, beans, squash, and slave natives, many of whom died enroute.

Spanish colonization

Spanish explorers came to what is now the United States beginning with Christopher Columbus' second expedition, which reached Puerto Rico on November 19, 1493. The first confirmed landing in the continental US was by a Spaniard, Juan Ponce de León, who landed in 1513 on a lush shore he christened La Florida.

Within three decades of Ponce de León's landing, the Spanish became the first Europeans to reach the Appalachian Mountains, the Mississippi River, the Grand Canyon and the Great Plains. In 1540, Hernando de Soto undertook an extensive exploration of the present US and, in the same year, Francisco Vázquez de Coronado led 2,000 Spaniards and Native Mexican Americans across the modern Arizona–Mexico border and traveled as far as central Kansas. Other Spanish explorers include Lucas Vásquez de Ayllón, Pánfilo de Narváez, Sebastián Vizcaíno, Juan Rodríguez Cabrillo, Gaspar de Portolà, Pedro Menéndez de Avilés, Álvar Núñez Cabeza de Vaca, Tristán de Luna y Arellano and Juan de Oñate.

The Spanish sent some settlers, creating the first permanent European settlement in the continental United States at St. Augustine, Florida in 1565. Later Spanish settlements included Santa Fe, Albuquerque, San Antonio, Tucson, San Diego, Los Angeles and San Francisco. Most Spanish settlements were along the California coast or the Santa Fe River in New Mexico.

Dutch colonization

Nieuw-Nederland, or New Netherland, was the seventeenth century Dutch colonial province on the eastern coast of North America. The claimed territory were the lands from the Delmarva Peninsula to Buzzards Bay, while the settled areas are now part of New Jersey, New York, Connecticut, Delaware, and Pennsylvania. Its capital, New Amsterdam, was located at the southern tip of the island of Manhattan on the Upper New York Bay and was renamed New York.

French colonization

New France was the area colonized by France in North America during a period extending from the exploration of the Saint Lawrence River, by Jacques Cartier in 1534, to the cession of New France to Spain and Britain in 1763. At its peak in 1712 (before the Treaty of Utrecht), the territory of New France extended from Newfoundland to the Rocky Mountains and from Hudson Bay to the Gulf of Mexico. The territory was divided in five colonies, each with its own administration: Canada, Acadia, Hudson Bay, Newfoundland and Louisiana.

Also during this period, French Huguenots, sailing under Jean Ribault, attempted to found a colony in what became the southeastern coast of the United States. Arriving in 1562, they established the ephemeral colony of Charlesfort on Parris Island in what is now South Carolina. When this failed, most of the colonists followed René Goulaine de Laudonnière and moved south, founding the colony of Fort Caroline at the mouth of the St. Johns River in what is now Jacksonville, Florida on June 22, 1564. Fort Caroline was destroyed in 1565 by the Spanish under Pedro Menéndez de Avilés, who moved in from St. Augustine, founded to the south earlier in the year.

British colonization

The strip of land along the eastern seacoast was settled primarily by English colonists in the 17th century, along with much smaller numbers of Dutch and Swedes. Colonial America was defined by a severe labor shortage that gave birth to forms of unfree labor such as slavery and indentured servitude, and by a British policy of benign neglect (salutary neglect) that permitted the development of an American spirit distinct from that of its European founders. Over half of all European migrants to Colonial America arrived as indentured servants.

The first successful English colony was established in 1607, on the James River at Jamestown. It languished for decades until a new wave of settlers arrived in the late 17th century and established commercial agriculture based on tobacco. Between the late 1610s and the Revolution, the British shipped an estimated 50,000 convicts to its American colonies. One example of conflict between Native Americans and English settlers was the 1622 Powhatan uprising in Virginia, in which Native Americans had killed hundreds of English settlers. The largest conflict between Native Americans and English settlers in the 17th century was King Philip's War in New England, although the Yamasee War may have been bloodier.

The Plymouth Colony was established in 1620. The area of New England was initially settled primarily by Puritans who established the Massachusetts Bay Colony in 1630. The Middle Colonies, consisting of the present-day states of New York, New Jersey, Pennsylvania, and Delaware, were characterized by a large degree of diversity. The first attempted English settlement south of Virginia was the Province of Carolina, with Georgia Colony the last of the Thirteen Colonies established in 1733. Several colonies were used as penal settlements from the 1620s until the American Revolution. Methodism became the prevalent religion among colonial citizens after the First Great Awakening, a religious revival led by preacher Jonathan Edwards in 1734.

Political integration and autonomy

The French and Indian War (1754–1763) was a watershed event in the political development of the colonies. The influence of the main rivals of the British Crown in the colonies and Canada, the French and North American Indians, was significantly reduced. Moreover, the war effort resulted in greater political integration of the colonies, as symbolized by Benjamin Franklin's call for the colonies to "Join or Die". Following Britain's acquisition of French territory in North America, King George III issued the Royal Proclamation of 1763 with the goal of organizing the new North American empire and stabilizing relations with the native Indians. In ensuing years, strains developed in the relations between the colonists and the Crown. The British Parliament passed the Stamp Act of 1765, imposing a tax on the colonies to help pay for troops stationed in North America following the British victory in the Seven Years' War. The British government felt that the colonies were the primary beneficiaries of this military presence, and should pay at least a portion of the expense. The colonists did not share this view. Rather, with the French and Indian threat diminished, the primary outside influence remained that of Britain. A conflict of economic interests increased with the right of the British Parliament to govern the colonies without representation being called into question. The Boston Tea Party in 1773 was a direct action by colonists in the town of Boston to protest against the taxes levied by the British government. Parliament responded the next year with the Coercive Acts, which sparked outrage and resistance in the Thirteen Colonies. Colonists convened the First Continental Congress to coordinate their resistance to the Coercive Acts. The Congress called for a boycott of British trade, published a list of rights and grievances, and petitioned the king for redress of those grievances.

The Congress also called for a another meeting in the event that their petition was unsuccessful in halting enforcement of the Coercive Acts. Their appeal to the Crown had no effect, and so the Second Continental Congress was convened in 1775 to organize the defense of the colonies at the onset of the American Revolutionary War.

Formation of the United States of America (1776–1789)

The Thirteen Colonies began a rebellion against British rule in 1775 and proclaimed their independence in 1776. They subsequently constituted the first thirteen states of the United States of America, which became a nation state in 1781 with the ratification of the Articles of Confederation and Perpetual Union. The 1783 Treaty of Paris represented the Kingdom of Great Britain's formal acknowledgement of the United States as an independent nation.

The United States defeated Britain with help from France, the United Provinces and Spain in the American Revolutionary War. The colonists' victory at Saratoga in 1777 led the French into an open alliance with the United States. It is a matter of debate which state was the first to recognize the United States, but the claim extends to the Republic of Ragusa (now the city of Dubrovnik)in Croatia, the Netherlands and Morocco.

In 1781, a combined American and French Army, acting with the support of a French fleet, captured a large British army led by General Charles Cornwallis at Yorktown, Virginia. The surrender of General Cornwallis ended serious British efforts to find a military solution to their American problem. In effect, "the United States was the first major colony successfully to revolt against colonial rule. In this sense, it was the first 'new nation'."

Side by side with the states' efforts to gain independence through armed resistance, a political union was being developed and agreed upon by them. The first step was to formally declare independence from Great Britain. On July 4, 1776, the Second Continental Congress, still meeting in Philadelphia, declared the independence of "the United States of America" in the Declaration of Independence. Although the states were still independent entities and not yet formally bound in a legal union, July 4 is celebrated as the nation's birthday. The new nation was dedicated to principles of republicanism, which emphasized civic duty and a fear of corruption and hereditary aristocracy.

A Union of the states with a constitutional government, the Congress of the Confederation first became possible with the ratification of the Articles of Confederation and Perpetual Union. The drafting of the Articles began in June 1776 and the approved text was sent to the States on November 15, 1777 for their ratification. While most States passed laws to authorize their representatives in Congress to sign the document by 1778, Maryland refused to do so until a dispute between the states concerning Western land claims had been resolved. After Virginia passed a law ceding its claims on January 2, 1781, Maryland became the 13th and final state to pass an Act to ratify the Articles on February 2, 1781. The formal signing of the Articles by Maryland was completed on March 1, 1781 in Philadelphia and on the following day Samuel Huntington became the first President of the United States in Congress Assembled. However, it became apparent early on that the new constitution was inadequate for the operation of the new government and efforts soon began to improve upon it.

A series of attempts to organize a movement to outline and press reforms culminated in the Congress calling the Philadelphia Convention in 1787. The structure of the national government was profoundly changed on March 4, 1789, when the American people replaced the confederation type government of the Articles with a federation type government of the Constitution. The new government reflected a radical break from the normative governmental structures of the time, favoring representative, elective government with a weak executive, rather than the existing monarchical structures common within the western traditions of the time. The system of republicanism borrowed heavily from the Enlightenment ideas and classical western philosophy: a primacy was placed upon individual liberty and upon constraining the power of government through a system of separation of powers. Additionally, the United States Bill of Rights was ratified on December 15, 1791 to guarantee individual liberties such as freedom of speech and religious practice and consisted of the first ten amendments of the Constitution. John Jay was the first Chief Justice of the Supreme Court, whose membership was established by the Judiciary Act of 1789; the first Supreme Court session was held in New York City on February 1, 1790. In 1803, the Court case Marbury v. Madison made the Court the sole arbiter of constitutionality of federal law.

Foundations for American government

Native American societies reminded Europeans of a golden age only known to them in folk history.

The idea of freedom and democratic ideals was born in the Americas because "it was only in America" that Europeans from 1500 to 1776 knew of societies that were "truly free."

The Iroquois nations' political confederacy and democratic government has been credited as one of the influences on the Articles of Confederation and the United States Constitution.

However, there is heated debate among historians about the importance of their contribution. Although Native American governmental influence is debated, it is a historical fact that several founding fathers had contact with the Iroquois, and prominent figures such as Thomas Jefferson and Benjamin Franklin were involved with the Iroquois.

Westward expansion (1789–1849)

George Washington—a renowned hero of the American Revolutionary War, commander-in-chief of the Continental Army, and president of the Constitutional Convention—became the first President of the United States under the new US Constitution. The Whiskey Rebellion in 1794, when settlers in the Pennsylvania counties west of the Allegheny Mountains protested against a federal tax on liquor and distilled drinks, was the first serious test of the federal government. At the end of his second presidential term, George Washington made his farewell address, which was published in the newspaper Independent Chronicle on September 26, 1796. In his address, Washington triumphed the benefits of federal government and importance of ethics and morality while warning against foreign alliances and formation of political parties. His vice-president John Adams succeeded him in presidency; Adams was a member of the Federalist Party. However, the Federalists became divided after Adams sent a peace mission to France despite ongoing disputes with that nation. Thomas Jefferson, a Democratic-Republican, defeated Adams for the presidency in the 1800 election.

The Louisiana Purchase, in 1803, removed the French presence from the western border of the United States and provided US settlers with vast potential for expansion west of the Mississippi River. Slave importation from Africa became illegal in 1808, despite a growing plantation system in many southern states such as North Carolina and Georgia. In response to continued British impressment of American sailors into the Royal Navy, the Congress declared war on Britain in 1812. The United States and Britain came to a draw in the War of 1812 after bitter fighting that lasted until January 8, 1815, during the Battle of New Orleans. The Treaty of Ghent, officially ending the war, essentially resulted in the maintenance of the status quo ante bellum; however, crucially for the US, some Native American tribes had to sign treaties with the US government because of their losses in the war. During the later course of the war, the Federalists held the Hartford Convention in 1814 over concerns that the war would weaken New England. There, they proposed seven constitutional amendments meant to strengthen the region politically, but by the time the Federalists delivered them to Washington, DC, the recent American victories in New Orleans and the signing of the Treaty of Ghent undermined the Federalists' arguments and contributed to the downfall of the party.

The Monroe Doctrine, expressed in 1823, proclaimed the United States' opinion that European powers should no longer colonize or interfere in the Americas. This was a defining moment in the foreign policy of the United States. The Monroe Doctrine was adopted in response to US and British fears over Russian and French expansion into the Western Hemisphere. It was not until the administration of Theodore Roosevelt that the Monroe Doctrine became a central tenet of US foreign policy. The Monroe Doctrine was then invoked in the Spanish-American War as well as later when Nicaragua sought aid from the Soviet Union.

In 1830, Congress passed the Indian Removal Act, which authorized the president to negotiate treaties that exchanged Native American tribal lands in the eastern states for lands west of the Mississippi River. This established Andrew Jackson, a military hero and President, as a cunning tyrant in regards to native populations. The act resulted most notably in the forced migration of several native tribes to the West, with several thousand people dying en route, and the Creeks' violent opposition and eventual defeat. The Indian Removal Act also directly caused the ceding of Spanish Florida and led to the many Seminole Wars. In its mission to end slavery, the abolitionist movement gained a large following from both black and white races. The American Anti-Slavery Society was politically active from 1833 to 1839 for the government to abolish slavery, but Congress imposed a "gag rule" that rejected any citizen's request against slavery. William Lloyd Garrison, formerly associated with the Society, then began publication of the anti-slavery newspaper The Liberator in Boston, Massachusetts in 1831, and Frederick Douglass, an ex-slave, began writing for that newspaper around 1840 and started his own abolitionist newspaper North Star in 1847.

The Republic of Texas was annexed by president John Tyler in 1845. The US army, using regulars and large numbers of volunteers, defeated Mexico in 1848 during the Mexican-American War. Public sentiment in the US was divided as Whigs and anti-slavery forces opposed the war. The 1848 Treaty of Guadalupe Hidalgo ceded California, New Mexico, and adjacent areas to the United States, about thirty percent of Mexico. Westward expansion was enhanced further by the California Gold Rush, the discovery of gold in that state in 1848. Numerous "forty-niners" trekked to California in pursuit of gold; land-hungry European immigrants also contributed to the rising white population in the west. In 1849 cholera spread along the California and Oregon Trails. It is estimated that over 150,000 Americans died during the two cholera pandemics between 1832 and 1849.

Civil War era (1849–1865)

In the middle of the 19th century, white Americans of the North and South were to reconcile fundamental differences in their approach to government, economics, society and African American slavery. The issue of slavery in the new territories was settled by the Compromise of 1850 brokered by Whig Henry Clay and Democrat Stephen Douglas; the Compromise included admission of California as a free state and the passage of the Fugitive Slave Act to make it easier for masters to reclaim runaway slaves. In 1854, the proposed Kansas-Nebraska Act abrogated the Missouri Compromise by providing that each new state of the Union would decide its stance on slavery. By 1860, there were nearly four million slaves residing in the United States, nearly eight times as many from 1790; within the same time period, cotton production in the U.S. boomed from less than a thousand tons to nearly one million tons per year. There were some slave rebellions – including by Gabriel Prosser (1800), Denmark Vesey (1822), and Nat Turner (1831) – but they all failed and led to tighter slave oversight in the south.

After Abraham Lincoln won the 1860 Election, eleven Southern states seceded from the union between late 1860 and 1861, establishing a rebel government, the Confederate States of America, on February 8, 1861.

The Civil War began on April 12, 1861, when Confederate forces attacked a US military installation at Fort Sumter in South Carolina. Along with the northwestern portion of Virginia, four of the five northernmost "slave states" did not secede and became known as the Border States.

In response to this, on April 15, Lincoln called on the states to send detachments totaling 75,000 troops to recapture forts, protect the capital, and "preserve the Union", which in his view still existed intact despite the actions of the seceding states. The two armies had their first major clash at the First Battle of Bull Run, which ended in a surprising Union defeat, but, more importantly, proved to both the Union and Confederacy that the war was going be much more longer and bloodier than they had originally anticipated.

The war soon divided into two theaters, the Eastern and Western theaters. In the western theater, the Union was quite successful, with major battles, such as Perryville ending up being strategic Union victories, destroying major confederate operations.

Things in the East, however, were not as successful. Many of the Union armies (most notably the Army of the Potomac) ended up having commanders who had serious flaws in them example- George B. McClellan always overestimating the size of the enemy) while Confederate commanders (the most famous being Robert E. Lee and Stonewall Jackson) were most of the time master strategists who utilized their available resources to their advantage. Because of this, the Union ended up losing to the Confederates at often bloody and humiliating battles (Battles of Fredericksburg and Chancellorsville). However, things changed for the Union when North Carolinians under Brig. Gen. J. Johnston Pettigrew noticed Union cavalry under Brig. Gen. John Buford arriving south of the town of Gettysburg. The resulting three-day Battle of Gettysburg ended up being the bloodiest battle of the Civil War and is considered by many historians to be the turning point of the war.

On the following day in the west, Union forces under the command of General Ulysses S. Grant gained control of the Mississippi River at the Battle of Vicksburg, thereby splitting the Confederacy. At the beginning of 1864, Lincoln made General Grant commander of all Union armies. The following two years of the war ended up being bloody for both sides, with Grant launching a war of attrition against Confederate General Robert E. Lee's Army of Northern Virginia. This war of attrition was divided into three main campaigns. The first of these, the Overland Campaign forced Lee to retreat into the city of Petersburg where Grant launched his second major offensive, the Richmond-Petersburg Campaign in which he sieged the city of Petersburg. After a near ten-month siege, the city of Petersburg surrendered. However, the defense of Fort Gregg allowed Lee to move his army out of Petersburg. Grant pursued and launched the final, Appomattox Campaign which resulted in Lee surrendering his Army of Northern Virginia on April 9, 1865, at Appomattox Court House.. When word of Lee's surrender spread across the country, many Confederate armies also surrendered, with Stand Watie being the last of the generals.

Based on 1860 census figures, 8% of all white males aged 13 to 43 died in the war, including 6% in the North and an extraordinary 18% in the South, marking the American Civil War to be the deadliest war in American history. Its legacy includes ending slavery in the United States, restoring the Union, and strengthening the role of the federal government. The social, political, economic and racial issues of the war decisively shaped the reconstruction era that lasted to 1877, and brought changes that helped make the country a united superpower.

Reconstruction and the rise of industrialization (1865–1890)

Reconstruction took place for most of the decade following the Civil War. During this era, the "Reconstruction Amendments" were passed to expand civil rights for black Americans. Those amendments included the Thirteenth Amendment, which outlawed slavery, the Fourteenth Amendment that guaranteed citizenship for all people born or naturalized within U.S. territory, and the Fifteenth Amendment that granted the vote for all men regardless of race. While the Civil Rights Act of 1875 forbade discrimination in the service of public facilities, the Black Codes denied blacks certain privileges readily available to whites. In response to Reconstruction, the Ku Klux Klan (KKK) emerged around the late 1860s as a white-supremacist organization opposed to black civil rights. Increasing hate-motivated violence from groups like the Klan influenced both the Ku Klux Klan Act of 1870 that classified the KKK as a terrorist group and an 1883 Supreme Court decision nullifying the Civil Rights Act of 1875; however, in the Supreme Court case United States v. Cruikshank the Court interpreted the Fourteenth Amendment as regulating only states' decisions regarding civil rights. The case defeated any protection of blacks from terrorist attacks, as did the later case United States v. Harris. During the era, many regions of the southern U.S. were military-governed and often corrupt; Reconstruction ended after the disputed 1876 election between Republican candidate Rutherford B. Hayes and Democratic candidate Samuel J. Tilden. Hayes won the election, and the South soon re-entered the national political scene.

Following was the Gilded Age, a term that author Mark Twain used to describe the period of the late nineteenth century when there had been a dramatic expansion of American industry. Reform of the Age included the Civil Service Act, which mandated a competitive examination for applicants for government jobs. Other important legislation included the Interstate Commerce Act, which ended railroads' discrimination against small shippers, and the Sherman Antitrust Act, which outlawed monopolies in business. Twain believed that this age was corrupted by such elements as land speculators, scandalous politics, and unethical business practices. By century's end, American industrial production and per capita income exceeded those of all other world nations and ranked only behind Great Britain. In response to heavy debts and decreasing farm prices, farmers joined the Populist Party. Later, an unprecedented wave of immigration served both to provide the labor for American industry and create diverse communities in previously undeveloped areas. From 1880 to 1914, peak years of immigration, more than 22 million people migrated to the United States. Abusive industrial practices led to the often violent rise of the labor movement in the United States. Influential figures of the period included John D. Rockefeller and Andrew Carnegie.

Progressivism, imperialism, and World War I (1890–1918)

After the Gilded Age came the Progressive Era, whose followers called for reform over perceived industrial corruption. Viewpoints taken by progressives included greater federal regulation of anti-trust laws and the industries of meat-packing, drugs, and railroads. Four new constitutional amendments—the Sixteenth through Nineteenth—resulted from progressive activism. The era lasted from 1900 to 1918, the year marking the end of World War I.

U.S. Federal government policy, since the James Monroe Administration, had been to move the indigenous population beyond the reach of the federal frontier into a series of Indian reservations. Tribes were generally forced onto small reservations as farmers and ranchers took over their lands.

The United States began its rise to international power in this period with substantial population and industrial growth domestically and numerous military ventures abroad, including the Spanish-American War, which began when the United States blamed the sinking of the on Spain. Also at stake were U.S. interests in acquiring Cuba, an island nation fighting for independence from Spanish occupation; Puerto Rico and the Philippines were also two former Spanish colonies seeking liberation. In December 1898, representatives of Spain and the U.S. signed the Treaty of Paris to end the war, with Cuba becoming an independent nation and Puerto Rico, Guam, and the Philippines becoming U.S. territories. In 1900, Congress passed the Open Door Policy that at the time required China to grant equal trading access to all foreign nations.

President Woodrow Wilson declared U.S. entry into World War I in April 1917 following a yearlong neutrality policy; the U.S. had previously shown interest in world peace by participating in the Hague Conferences. American participation in the war proved essential to the Allied victory. Wilson also implemented a set of propositions titled the Fourteen Points to ensure peace, but they were denied at the 1919 Paris Peace Conference. Isolationist sentiment following the war also blocked the U.S. from participating in the League of Nations, an important part of the Treaty of Versailles.

Women's suffrage

These years of the early 20th century also saw the strengthening of the Woman Suffrage Movement. The movement had begun with the 1848 Seneca Falls Convention, organized by Elizabeth Cady Stanton and Lucretia Mott, and the Declaration of Sentiments demanding equal rights for women. The women's rights campaign during "first-wave feminism" was led by Mott, Stanton, Susan B. Anthony, Sojourner Truth, Lucy Stone, and Julia Ward Howe, among others. By the end of the 19th century only several states had granted women full voting rights, though women had made significant legal victories, gaining rights in areas such as property and child custody. In 1875 the Supreme Court ruled women, too, were American citizens (but this did not give them the right to vote).

Around 1912 the Feminist Movement, which had grown sluggish, began to reawaken. Protests became increasingly common as suffragette Alice Paul led parades through the capital and major cities. Paul split from the large National American Woman Suffrage Association (NAWSA), which favored a more moderate approach and supported the Democratic Party and Woodrow Wilson, led by Carrie Chapman Catt, and formed the more militant National Woman's Party. Suffragists were arrested during their "Silent Sentinal" pickets at the White House, the first time such a tactic was used, and were taken as political prisoners. In prison they were tortured and force-fed while on hunger strikes led by Alice Paul. Finally, the suffragette were ordered released from prison, and Wilson addressed the Congress on woman suffrage, urging them to pass a Constitutional amendment enfranchising women, which they did in 1919. It became constitutional law on August 26, 1920, after ratification by the 36th required state. NAWSA became the League of Women Voters and the National Woman's Party began lobbying for full equality and the Equal Rights Amendment which would pass Congress during the second wave of the women's movement in 1972. Following ratification of the Nineteenth Amendment, a U.S. Court ruled the arrests of the over two hundred suffragists as unconstitutional, and the amendment was upheld by the Supreme Court after a legal challenge.

Post-World War I and the Great Depression (1918–1940)

Following World War I, the U.S. grew steadily in stature as an economic and military world power. The United States Senate did not ratify the Treaty of Versailles imposed by its Allies on the defeated Central Powers; instead, the United States chose to pursue unilateralism, if not isolationism. The aftershock of Russia's October Revolution resulted in real fears of communism in the United States, leading to a three-year Red Scare and the U.S. lost 675,000 people to the Spanish flu pandemic in 1918.

In 1920, the manufacture, sale, import and export of alcohol was prohibited by the Eighteenth Amendment to the United States Constitution. Prohibition encouraged illegal breweries and dealers to make substantial amounts of money selling alcohol illegally. The Prohibition ended in 1933, a failure. Additionally, the KKK re-formed during that decade and gathered nearly 4.5 million members by 1924, and the U.S. government passed the Immigration Act of 1924 restricting foreign immigration. The 1920s were also known as the Roaring Twenties, due to the great economic prosperity during this period. Jazz became popular among the younger generation, and thus was also called the Jazz Age.

During most of the 1920s, the United States enjoyed a period of unbalanced prosperity: farm prices and wages fell, while new industries, and industrial profits grew. The boom was fueled by an inflated stock market, which later led to a crash on October 29, 1929. The Hawley-Smoot Tariff, the Dust Bowl, and the ensuing Great Depression led to government efforts to restart the economy and help its victims with Franklin D. Roosevelt's New Deal. The recovery was rapid in all areas except unemployment, which remained fairly high until 1940.

World War II (1941–1945)

As with World War I, the United States did not enter World War II until after the rest of the active Allied countries had done so. The United States first contribution to the war was simultaneously to cut off the oil and raw material supplies needed by Japan to maintain its offensive in China, and to increase military and financial aid to China. Contribution came to the Allies in September 1940 in the form of the Lend-Lease program with Britain.

On December 7, 1941 Japan launched a surprise attack on the American naval base in Pearl Harbor, citing America's recent trade embargo as justification. The following day, Franklin D. Roosevelt successfully urged a joint session of Congress to declare war on Japan, calling December 7, 1941 "a date which will live in infamy". Four days after the attack on Pearl Harbor, on December 11, Nazi Germany declared war on the United States, drawing the country into a two-theater war.

Battle against Germany

Upon entering the war, the United States and its allies decided to concentrate the bulk of their efforts on fighting Hitler in Europe, while maintaining a defensive position in the Pacific until Hitler was defeated. The United States's first step was to set up a large airforce in Britain to concentrate on bombing raids into Germany itself. The American Air force relied on the B-17 Flying Fortress as its primary heavy bomber. Britain had ceased its daylight bombing raids, due to heavy casualties inflicted by the Luftwaffe. The USAAF suffered similar high losses until the introduction of the P-51 Mustang as a long range escort fighter for the bombers. The American army's first ground action was fighting alongside the British, Australian and New Zealand armies in North Africa. By May 1943, the British 8th Army had expelled the Germans from North Africa and the Allies controlled this vital link until the end of the war. The American navy also played an active role in the Atlantic protecting the convoys bringing vital American war material to Britain. By midway through 1943, the Allies were fighting the war from Britain with unbroken supply lines, while at the same time Hitler's armies were very much on the back foot, with heavy bombing taking its toll on production.

By early 1944, a planned invasion of Western Europe was underway. What followed on June 6, 1944, was Operation Overlord, or D-Day. The largest war armada ever assembled landed on the beaches of Normandy and began the penetration of Western Europe that eventually overthrew Hitler and Nazi Germany. Following the landing at Normandy, the Americans contributed greatly to the outcome of the war, with dogged fighting in the Battle of the Ardennes and the Battle of the Bulge resulting in Allied victories against the Germans. The battles took a heavy toll on the Americans, who lost 19,000 men during the Battle of the Bulge alone. The allied bombing raids on Germany increased to unprecedented levels after the D-Day invasion, with over 70% of all bombs dropped on Germany occurring after this date. On April 30, 1945, with Berlin completely overrun with Russian forces and his country in tatters, Adolf Hitler committed suicide. On May 8, 1945, the war with Germany was over, following its unconditional surrender to the Allied forces.

Battle against Japan

Due to the United States commitment to defeating Hitler in Europe, the first years of the war against Japan was largely a defensive battle with the United States Navy attempting to prevent the Japanese Navy from asserting dominance of the Pacific region. Initially, Japan won the majority of its battles in a short period of time. Japan quickly defeated and created military bases in Guam, Thailand, Malaya, Hong Kong, Papua New Guinea, Indonesia and Burma. This was done virtually unopposed and with quicker speed than that of the German Blitzkrieg during the early stages of the war. This was important for Japan, as it had only 10% of the homeland industrial production capacity of the United States.

The turning point of the war was the Battle of Midway in June 1942. Following this, the Americans began fighting towards China where they could build an airbase suitable to commence bombing of mainland Japan with its B-29 Superfortress fleet. The Americans began by selecting smaller, lesser defended islands as targets as opposed to attacking the major Japanese strongholds. During this period, they inadvertently triggered what would become their most comprehensive victory in the entire war.

The Pacific war became the largest naval conflict in history. The American Navy emerged victorious, after at one point being stretched near to the breaking point, with almost complete destruction of the Japanese Navy. The American forces were then poised for an invasion of the Japanese mainland, to force the Japanese into unconditional surrender. On April 12, 1945, President Franklin D. Roosevelt died and Vice President Harry S. Truman was sworn in as the 33rd President of the United States. The use of atomic weapons against Japan was subsequently authorized. The decision to use nuclear weapons to end the conflict has been one of the most controversial decisions of the war. Supporters of the use of the bombs argue that an invasion would have cost an enormous numbers of lives, while opponents argue that the large number of civilian casualties resulting from the bombings was unjustified. The first bomb was dropped on Hiroshima on August 6, 1945, and the second bomb was dropped on Nagasaki on August 9, 1945. On August 15, 1945, the Japanese surrendered unconditionally, ending World War II.

The Cold War begins (1945–1964)

Following World War II, the United States emerged as one of the two dominant superpowers. The U.S. Senate, on December 4, 1945, approved U.S. participation in the United Nations (UN), which marked a turn away from the traditional isolationism of the U.S. and toward more international involvement. The post-war era in the United States was defined internationally by the beginning of the Cold War, in which the United States and the Soviet Union attempted to expand their influence at the expense of the other, checked by each side's massive nuclear arsenal and the doctrine of mutual assured destruction. The result was a series of conflicts during this period including the Korean War and the tense nuclear showdown of the Cuban Missile Crisis. Within the United States, the Cold War prompted concerns about Communist influence, and also resulted in government efforts to focus mathematics and science toward efforts such as the space race.

In the decades after World War II, the United States became a global influence in economic, political, military, cultural, and technological affairs. Beginning in the 1950s, middle-class culture had a growing obsession with consumer goods.

John F. Kennedy was elected President in 1960. Known for his charisma, he is so far the only Roman Catholic to be President. The Kennedy's brought a new life and vigor to the atmosphere of the White House. During his time in office, the Cold War reached its height with the Cuban Missile Crisis in 1962. He was assassinated in Dallas, Texas, on November 22, 1963 by Lee Harvey Oswald.

The Civil Rights Movement (1955–1970)

Meanwhile, the American people completed a great migration from farms into the cities and experienced a period of sustained economic expansion. At the same time, institutionalized racism across the United States, but especially in the American South, was increasingly challenged by the growing Civil Rights movement. The activism of African American leaders Rosa Parks and Martin Luther King, Jr. led to the Montgomery Bus Boycott, which launched the movement. For years African Americans would struggle with violence against them, but would achieve great steps towards equality with Supreme Court decisions, including Brown v. Board of Education and Loving v. Virginia, the Civil Rights Act of 1964, the Voting Rights Act of 1965, and the Fair Housing Act of 1968, which ended the Jim Crow laws that legalized racial segregation between Whites and Blacks. Martin Luther King, Jr., who had won the Nobel Peace Prize for his efforts to achieve equality of the races, was assassinated in 1968. Following his death other leaders led the movement, most notably King's widow, Coretta Scott King, who was also active, like her husband, in the Opposition to the Vietnam War, and in the Women's Liberation Movement. Over the first nine months of 1967, 128 American cities suffered 164 riots. The late 1960s and early 1970s saw the strengthening of Black Power, however the decade would ultimately bring about positive strides toward integration.

The Women's Movement (1963–1982)

A new consciousness of the inequality of American women began sweeping the nation, starting with the 1963 publication of Betty Friedan's best-seller, The Feminine Mystique, which explained how many housewives felt trapped and unfulfilled, assaulted American culture for its creation of the notion that women could only find fulfillment through their roles as wives, mothers, and keepers of the home, and argued that women were just as able as men to do every type of job. In 1966 Friedan and others established the National Organization for Women, or NOW, to act as an NAACP for women. Protests began, and the new "Women's Liberation Movement" grew in size and power, gained much media attention, and, by 1968, had replaced the Civil Rights Movement as the U.S.'s main social revolution. Marches, parades, rallies, boycotts, and pickets brought out thousands, sometimes millions; Friedan's Women's Strike for Equality (1970) was a nation-wide success. The Movement was factioned early on, however (NOW on the left, the Women's Equity Action League (WEAL) on the right, the National Women's Political Caucus (NWPC) in the center, and more radical groups formed by younger women on the far left). Along with Friedan, Gloria Steinem was an important feminist leader, co-founding the NWPC, the Women's Action Alliance, and editing the Movement's magazine, Ms. The proposed Equal Rights Amendment to the Constitution, passed by Congress in 1972 and favored by about seventy percent of the American public, failed to be ratified in 1982, with only three more states needed to make it law. However many federal laws (i.e. those equalizing pay, employment, education, employment opportunites, credit, ending pregnancy discrimination, and requiring NASA, the Military Academies, and other organizations to admit women), state laws (i.e. those ending spousal abuse and marital rape), Supreme Court rulings (i.e. ruling the equal protection clause of the Fourteenth Amendment applied to women), and state ERAs established women's equal status under the law, and social custom and consciousness began to change, accepting women's equality. The controversial issue of abortion, legalized in 1973 is still a point of feminist debate today.

The Counterculture Revolution and Cold War Détente (1964–1980)

Amid the Cold War, the United States entered the Vietnam War, whose growing unpopularity fed already existing social movements, including those among women, minorities and young people. President Lyndon B. Johnson's Great Society social programs and the judicial activism of the Warren Court added to the wide range of social reform during the 1960s and 1970s. Feminism and the environmental movement became political forces, and progress continued toward civil rights for all Americans. The Counterculture Revolution swept through the nation and much of the western world in the late sixties and early seventies, dividing the already hostile environment but also bringing forth more liberated social views.

Johnson was succeeded by President Richard Nixon in 1969, who initially escalated the Vietnam War but soon was able to negotiate a peace treaty in 1973, effectively ending American involvement in the war. The war had cost the lives of 58,000 American troops and millions of Vietnamese. Nixon used a conflict in the Eastern Bloc between the Soviet Union and China to the advantage of the United States, bolstering relations with the People's Republic of China. A new era of Cold War relations known as détente (cooperation) was begun. The OPEC oil embargo led to a period of slow economic growth in 1973. Nixon's administration was brought to an ignominious close with the political scandal of Watergate in August 1974. During the years of his successor, Gerald Ford, the American-backed South Vietnamese government collapsed.

Jimmy Carter was elected in 1976 on the notion that he was not a part of the Washington political establishment. The U.S. was afflicted with a recession, an energy crisis, slow economic growth, high unemployment, and high inflation coupled with high interest rates (the term stagflation was coined). On the world stage, Carter brokered the Camp David Accords between Israel and Egypt. In 1979, Iranian students stormed the U.S. embassy in Tehran and took 52 Americans hostage. Carter lost the 1980 election to Republican Ronald Reagan, whose campaign message advertised that his presidency would bring "Morning in America."

The end of the Cold War (1980–1991)

Ronald Reagan produced a major realignment with his 1980 and 1984 landslides. In 1980, the Reagan coalition was possible because of Democratic losses in most social-economic groups. "Reagan Democrats" were those who usually voted Democratic, but were attracted by Reagan's policies, personality and leadership, notably his social conservatism and hawkish foreign policy. Reagan's economic policies (dubbed "Reaganomics") and the implementation of the Economic Recovery Tax Act of 1981 lowered income taxes from 70% to 28% over the course of seven years. Reagan continued to downsize government taxation and regulation. The U.S. experienced a recession in 1982; unemployment and business failures soon entered rates close to Depression-era levels. These negative trends reversed the following year, when the inflation rate decreased from 11% to 2%, the unemployment rate decreased to 7.5%, and the economic growth rate increased from 4.5 to 7.2%.

Reagan took a hard line against the Soviet Union, proclaiming it to be the Evil Empire. Reagan ordered a massive buildup of the U.S. military, incurring a costly budget deficit. Reagan introduced a complicated missile defense system known as the Strategic Defense Initiative (dubbed "Star Wars" by opponents) in which the U.S. could, in theory, shoot down missiles by means of laser systems in space. Though it was never fully developed or deployed, the Soviets were genuinely concerned about the possible effects of the program and the research and technologies of SDI paved the way for the anti-ballistic missile systems of today. The Reagan administration also provided covert funding and assistance to anti-Communist resistance movements worldwide. Reagan's interventions against Grenada and Libya were popular in the U.S., though his backing of the Contra rebels was mired in controversy. The arms-for-hostages scandal led to the convictions of such figures as Oliver North and John Poindexter. He shared many common views and goals with friend and ally Margaret Thatcher, the Prime Minister of the United Kingdom.

Reagan met with Soviet Leader Mikhail Gorbachev, who ascended to power in 1985, four times, and their summit conferences led to the signing of the INF Treaty. Gorbachev tried to save Communism in the Soviet Union first by ending the expensive arms race with America, then by shedding the East European empire in 1989. The Soviet Union collapsed in 1991, ending the US-Soviet Cold War.

The "World Superpower" (1991–present)

After the fall of the Soviet Union, the United States emerged as the world's sole remaining superpower and continued to involve itself in military action overseas, including the 1991 Gulf War. Following his election in 1992, President Bill Clinton oversaw unprecedented gains in securities values, a side effect of the digital revolution and new business opportunities created by the Internet (see Internet bubble). The 1990s saw one of the longest periods of economic expansion. Under Clinton an attempt to universalize health care, led by First Lady Hillary Rodham Clinton failed after almost two years of work on the controversial plan, however Hillary Rodham Clinton did succeed, along with a bipartisan coalition of members of congress, to establish the Children's Health Insurance Program.

The regime of Saddam Hussein in Iraq proved a continuing problem for the UN and Iraq's neighbors in its refusal to account for previously known stockpiles of chemical and biological weapons, its violations of UN resolutions, and its support for terrorism against Israel and other countries. After the 1991 Gulf War, the US, French, and British military's began patrolling the Iraqi no-fly zones to protect Iraq's Kurdish minority and Shi’ite Arab population – both of which suffered attacks from the Hussein regime before and after the 1991 Gulf War – in Iraq's northern and southern regions, respectively. In the aftermath of Operation Desert Fox during December 1998, Iraq announced that it would no longer respect the no-fly zones and resumed its efforts in shooting down Allied aircraft.

During the 1990s the al-Qaeda terrorist network and other Islamic fundamentalist groups attempted terrorist attacks against the United States and other nations. In 1993, Ramzi Yousef, a Kuwaiti national, and suspected al-Qaeda operative, planted explosives in the underground garage of One World Trade Center and detonated them, killing six people and injuring thousands. Later that year in the Battle of Mogadishu, US Army Rangers engaged Somali militias supported by al-Qaeda in an extended firefight that cost the lives of 19 soldiers. President Clinton subsequently withdrew US combat forces from Somalia (there originally to support UN relief efforts). Terrorist attacks occurred in the 1996 Khobar Towers bombing in Saudi Arabia, and the 1998 United States embassy bombings in Tanzania and Kenya. There was an attempted bombing at Los Angeles International Airport and other attempts of acts of terrorism during the 2000 millennium attack plots. In Yemen the USS Cole was bombed in October 2000, which the government associated with Osama bin Laden's al-Qaeda terrorist network.

US responses to terrorist attacks included limited cruise missile strikes on Afghanistan and Sudan , which failed to stop al-Qaeda's leaders and their Taliban supporters. Also in 1998, President Clinton signed the Iraq Liberation Act which called for regime change in Iraq on the basis of Saddam Hussein's possession of weapons of mass destruction, oppression of Iraqi citizens and attacks upon other Middle Eastern countries.

Al-Qaeda and other Islamic fundamentalist groups were not the only groups responsible for terrorism during this time. In 1995, a domestic terrorist bombing took place at a federal building in Oklahoma City, which killed 168 people, and was the biggest terrorist attack on US soil since World War II at the time. The perpetrators, Timothy McVeigh and Terry Nichols, objected to the federal government and in particular sought revenge for the sieges at Ruby Ridge (1992) and Waco (1993).

In 1998, Clinton was impeached for charges of perjury and obstruction of justice that arose from lying about a sexual relationship with White House intern Monica Lewinsky. He was the second president to have been impeached. The House of Representatives voted 228 to 206 on December 19 to impeach Clinton, but on February 12, 1999, the Senate voted 55 to 45 to acquit Clinton of the charges.

The presidential election in 2000 between George W. Bush (R) and Al Gore (D) was one of the closest in the U.S. history, and helped lay the seeds for political polarization to come. Although Bush won the majority of electoral votes, Gore won the majority of the popular vote. In the days following Election Day, the state of Florida entered dispute over the counting of votes due to technical issues over certain Democratic votes in some counties. The Supreme Court case Bush v. Gore was decided on December 12, 2000, ending the recount with a 5–4 vote and certifying Bush as president.



At the beginning of the new millennium, the United States found itself attacked by Islamic terrorism, with the September 11, 2001 attacks in which 19 extremists hijacked four transcontinental airliners and intentionally crashed two of them into the twin towers of the World Trade Center and one into the Pentagon. The passengers on the fourth plane, United Airlines Flight 93, revolted causing the plane to crash into a field in Somerset County, Pennsylvania. 2,976 people and the 19 hijackers perished in the attacks. According to the 9/11 Commission Report, that plane was intended to hit the US Capitol Building in Washington. The twin towers of the World Trade Center collapsed, destroying the entire complex. The United States soon found large amounts of evidence that suggested that the terrorist group al-Qaeda, spearheaded by Osama bin Laden, was responsible for the attacks.

In response to the attacks, under the administration of President George W. Bush, the United States (with the military support of NATO and the political support of some of the international community) launched Operation Enduring Freedom which overthrew the Taliban regime in Afghanistan which had protected and harbored bin Laden and al-Qaeda. With the support of large bipartisan majorities, the US Congress passed the Authorization for Use of Military Force Against Iraq Resolution of 2002. With a coalition of other countries including Britain, Spain, Australia, Japan and Poland, in March 2003 President Bush ordered an invasion of Iraq dubbed Operation Iraqi Freedom which led to the overthrow and capture of Saddam Hussein. Using the language of 1998 Iraq Liberation Act and the Clinton Administration, the reasons cited by the Bush administration for the invasion included the spreading of democracy, the elimination of weapons of mass destruction (a key demand of the UN as well, though later investigations found parts of the intelligence reports to be inaccurate) and the liberation of the Iraqi people. This second invasion fueled protest marches in many parts of the world.

Despite tougher border scrutiny after 9/11, nearly 8 million immigrants came to the United States from 2000 to 2005 – more than in any other five-year period in the nation's history. Almost half entered illegally. In August 2005, Hurricane Katrina flooded parts of the city of New Orleans and heavily damaged other areas of the gulf coast, including major damage to the Mississippi coast. The preparation and the response of the government were criticized as ineffective and slow.

By 2006, rising prices saw Americans become increasingly conscious of the nation's dependence on supplies of petroleum for energy, with President Bush admitting a U.S. "addiction" to oil. The possibility of serious economic disruption, should conflict overseas or declining production interrupt the flow, could not be ignored, given the instability in the Middle East and other oil-producing regions of the world. Many proposals and pilot projects for replacement energy sources, from ethanol to wind power and solar power, received more capital funding and were pursued more seriously in the 2000s than in previous decades. The 2006 midterm elections saw Congresswoman Nancy Pelosi become Speaker of the United States House of Representatives and the highest ranking woman in the history of the U.S. government.

In addition to military efforts abroad, in the aftermath of 9/11 the Bush Administration increased domestic efforts to prevent future attacks. A new cabinet level agency called the United States Department of Homeland Security was created to lead and coordinate federal counter-terrorism activities. The USA PATRIOT Act removed legal restrictions on information sharing between federal law enforcement and intelligence services and allowed for the investigation of suspected terrorists using means similar to those in place for other types of criminals. A new Terrorist Finance Tracking Program monitored the movements of terrorists' financial resources but was discontinued after being revealed by The New York Times. Telecommunication usage by known and suspected terrorists was studied through the NSA electronic surveillance program.

Since 9/11, Islamic extremists made various attempts to attack the US homeland, with varying levels of organization and skill. For example, in 2001 vigilant passengers aboard a transatlantic flight to Miami prevented Richard Reid from detonating an explosive device.

After months of brutal violence against Iraqi civilians by Sunni and Shi’ite terrorist groups and militias—including al-Qaeda in Iraq—in January 2007 President Bush presented a new strategy for Operation Iraqi Freedom based upon counter-insurgency theories and tactics developed by General David Petraeus. The Iraq War troop surge of 2007 was part of this "new way forward" and has been credited by some with a dramatic decrease in violence and an increase in political and communal reconciliation in Iraq.

As of 2009, debates continue over abortion, gun control, same-sex marriage, immigration reform, and the ongoing war in Iraq. Although the new Democratic Congressional majority promised to withdraw U.S. forces from Iraq, Congress continues to fund efforts in both Iraq and Afghanistan (however a withdrawal agreement has been agreed upon between the US and Iraqi governments). In the area of foreign policy, the U.S. maintains ongoing talks, led by United States Secretary of State Hillary Rodham Clinton, with North Korea over its nuclear weapons program, as well as with Israel and the Palestinian Authority over a two-state solution to the Israeli-Palestinian conflict; the Palestinian-Israeli talks began in 2007, an effort spearheaded by United States Secretary of State Condoleezza Rice. The George W. Bush administration also increased allegations implicating Iran, and more recently Syria, in the development of weapons of mass destruction.

In December 2007, the United States entered the longest post-World War II recession, which included a housing market correction, a subprime mortgage crisis, soaring oil prices, and a declining dollar value. In February 2008, 63,000 jobs were lost, a 5-year record for a single month. In September 2008, the crisis became much worse beginning with the government takeover of Fannie Mae and Freddie Mac followed by the collapse of Lehman Brothers. This economic crisis was considered the worst financial crisis since the Great Depression. By October 2009, the U.S. had lost a total of 8.2 million jobs, leaving the unemployment rate above 10% for the first time since 1983, and an underemployment rate of over 17%, the highest since records began being kept in 1994. China, holding an estimated $1.6 trillion of U.S. securities, is the largest foreign financier of the record U.S. public debt.

In the presidential election of 2008, Senator Barack Obama, having narrowly defeated Senator Hillary Rodham Clinton for the Democratic nomination, ran on a platform of "Hope and Change". This, coupled with the economic crisis, helped aid his and running-mate Joe Biden's victory against the Republican ticket of Senator John McCain and Governor Sarah Palin. On November 4, Obama became the first African American to be elected President of the United States; he was sworn into office as the 44th President on January 20, 2009.

See also

• The Almanac of American History (reference work)
• Cultural history of the United States
• Economic history of the United States
• History of agriculture in the United States
• History of education in the United States
• History of religion in the United States
• Military history of the United States
• Outline of the United States
• Outline of United States history
• Technological and industrial history of the United States
• Territorial evolution of the United States
• United States of America
• U.S. state
• :Category:History of the United States
  • commons:Category:History of the United States
  • commons:Category:Territorial Growth Maps of the United States

Lists:

• Index of United States-related articles
• List of capitals in the United States
• List of conflicts in the United States
• List of Presidents of the United States
• List of United States treaties
• List of wars involving the United States

Timelines:

• Timeline of country and capital changes
• Timeline of United States history
• Timeline of United States military operations

Notes

References

Further reading

• Stein, Mark, How the States Got Their Shapes, New York : Smithsonian Books/Collins, 2008. ISBN 9780061431388

External links

• Outline of U.S. History by the U. S. Department of State
• U.S. National Archives
• American Historical Association
• American History Calendar Interactive calendar of events and people in American history
• Journal of American History
• Colored Timeline of American History broken down by theme
• BackStory - Public Radio show exploring American History