The
Mexican Cession of 1848 is a historical name in
the United States for the region of the present day southwestern United States
that Mexico
ceded to the
U.S. in 1848, excluding the areas east of the Rio Grande
, which had been claimed by the Republic of Texas, though the Texas Annexation resolution two years
earlier had not specified Texas's southern and western
boundary.
The U.S.
had taken actual control of the Mexican territories of Santa Fe de Nuevo México and
Alta
California
in 1846
early in the Mexican-American
War, and Mexico acknowledged the loss of Texas, New Mexico, and
California in the Treaty of
Guadalupe Hidalgo, which was signed on February 2, 1848, ratified by the U.S. Senate on
March
10,
1848, and by the Mexican government on
May 19,
1848.
Background

A map of Mexico, 1835-1846 with
separatist movements highlighted.
The cession of this territory from Mexico was a major goal of the
war. California and New Mexico were captured soon after the start
of the war and the last resistance there was subdued in January
1847, but Mexico would not accept the loss of territory.
Therefore
during 1847 United States troops invaded central Mexico and
occupied the Mexican capital of Mexico City
, but still no Mexican government was willing to
ratify transfer of the northern territories to the U.S. It
was uncertain whether any treaty could be reached. There was even
an
All of Mexico Movement
proposing complete
annexation of Mexico
among Eastern Democrats, opposed by Southerners like
John Calhoun who wanted additional territory
for white Southerners and their black slaves but not the large
population of central Mexico. Eventually
Nicholas Trist negotiated the
Treaty of Guadalupe Hidalgo
ceding only California and New Mexico in early 1848 after President
Polk had already attempted to recall him from Mexico as a failure.
The U.S. Senate approved the treaty, rejecting amendments from
Jefferson Davis to also annex most
of
northeastern Mexico and by
Daniel Webster to not even take
California and New Mexico.
The United States also paid $15,000,000 ($298,310,309 in 2005) for
the land, and agreed to assume $3.25 million in debts to US
citizens. The land ceded by Mexico is 14.9% of the total area of
the current United States territory. 1.36 million km² (525000
square miles, or 55% of its pre-war territory) was lost by
Mexico.
As of July 1, 2007, the states of California, Nevada, Utah, Arizona
and New Mexico had a total population of 50,072,597 out of
305,986,357 nationwide, or 16.4% of the
US population.
For the years between 1821, when
Mexican independence was secured and
the
Texas Revolution in 1836, the
Mexican Cession had formed approximately 42% of the country of
Mexico; prior to that, it had been a part of the Spanish colony of
New Spain for some three centuries.
Beginning
in the early seventeenth century, a chain of Spanish missions and
settlements extended into the New Mexico region, mostly following
the course of the Rio
Grande
from the El Paso
area to
Santa
Fe
.
Territory
Total losses of 1848, Mexican view: white
The region
includes all of the present-day states of California
, Nevada
, and
Utah
; as well as portions of:
The
treaty also specified the international border between Texas and
Mexico as being at the Rio
Grande
(RÃo Bravo del Norte). Previously the
portion of Texas
between the
Nueces
River
and the Rio Grande had remained disputed throughout
the existence of the Republic of
Texas. The United States had already claimed the area as
part of the
Texas Annexation in
1845. Mexico had recognized neither.
The
portion of New
Mexico
east of the Rio Grande had been claimed by the
Republic of Texas and is therefore usually shown as part of the
Texas Annexation. In actuality New Mexico was never divided
at the Rio Grande, was never controlled by the Republic of Texas,
and was widely separated from Texas by the
Comancheria which was not under either Anglo or
Hispanic control.
Stephen Kearny's
U.S.
Army of
the West from Fort Leavenworth, Kansas
took New Mexico without resistance in 1846 early in
the Mexican-American War. It was quickly provided with its
own territorial government and was never governed by the State of
Texas.
Subsequent organization and the North-South conflict
Soon
after the war started and long before negotiation of the new
US-Mexico border, the question of
slavery in the territories to be acquired polarized the Northern
and Southern United States in
the bitterest sectional conflict up to this time, which lasted for
a deadlock of four years during which the Second Party System broke up, Mormon pioneers settled Utah
, the
California Gold Rush settled
California
, and New Mexico under a federal military government
turned back Texas
's attempt to
assert control over territory Texas claimed as far west as the
Rio
Grande
. Eventually the
Compromise of 1850 preserved the Union,
but only for another decade. Proposals included:
- The Wilmot Proviso,which was
created by Senator David Wilmot,
banning slavery in any new territory to be acquired from Mexico,
not including Texas which had been annexed the previous year.
Passed by the United States House of
Representatives in August 1846 and February 1847 but not the
Senate. Later an effort to
attach the proviso to the Treaty of Guadalupe Hidalgo also
failed.
- Failed amendments to the Wilmot Proviso by William W. Wick and
then Stephen Douglas extending the
Missouri Compromise line
(36°30' parallel north)
west to the Pacific, allowing slavery in most of present day
New
Mexico
and Arizona
, Las Vegas, Nevada
, and Southern
California, as well as any other territories that might be
acquired from Mexico. The line was again proposed by the
Nashville Convention of June
1850.
- Popular sovereignty,
developed by Lewis Cass and Douglas as
the eventual Democratic
Party position, letting each territory decide whether to allow
slavery.
- William L. Yancey's "Alabama Platform," endorsed by
the Alabama
and Georgia
legislatures and by Democratic state conventions in
Florida
and Virginia
, called for no restrictions on slavery in the
territories either by the federal government or by territorial
governments before statehood, opposition to any candidates
supporting either the Wilmot Proviso or popular sovereignty, and
federal legislation overruling Mexican anti-slavery
laws.
- General Zachary Taylor, who
became the Whig candidate
in 1848 and then President from March 1849 to July 1850, proposed
after becoming President that the entire area become two free
states, called California and New Mexico but much larger than the
eventual ones. None of the area would be left as an unorganized or
organized territory, avoiding
the question of slavery in the territories.
- The
Mormons' proposal for a State of
Deseret incorporating most of the area of the Mexican Cession
but excluding the largest non-Mormon populations in Northern California and central New Mexico
was considered unlikely to succeed in Congress, but nevertheless in 1849
President Taylor sent his agent
John Wilson westward
with a proposal to combine California and Deseret as a single
state, decreasing the number of new free states and the erosion of Southern
parity in the Senate.
- Senator Thomas Hart
Benton in December 1849 or January 1850: Texas's western and
northern boundaries would be the 102nd meridian west and 34th parallel north.
- Senator John Bell (with assent of
Texas) in February 1850: New Mexico would get all Texas land north
of the 34th parallel north
(including today's Texas Panhandle
), and the area to the south (including the
southeastern part of today's New Mexico
) would be divided at the Colorado River into two Southern
states, balancing the admission of California and New Mexico as
free states.
- First
draft of the compromise of 1850:
Texas's northwestern boundary would be a straight diagonal line
from the Rio
Grande
20 miles north of El Paso to the Red
River
at the 100th
meridian west (the southwestern corner of today's Oklahoma
).
- The Compromise of 1850,
proposed by Henry Clay in January 1850,
guided to passage by Douglas over Northern Whig and Southern
Democrat opposition, and enacted September 1850, admitted
California as a free state including Southern California and
organized Utah Territory and New Mexico Territory with slavery to be
decided by popular sovereignty. Texas dropped its claim to the
disputed northwestern areas in return for debt relief, and the
areas were divided between the two new territories and unorganized territory. El Paso
where Texas had successfully established county
government was left in Texas. No southern territory
dominated by Southerners (like the later short-lived Confederate Territory of
Arizona) was created. Also, the slave
trade was abolished in Washington, DC
(but not slavery itself), and the Fugitive Slave Act was
strengthened.
References
- Treaty of Guadalupe Hidalgo, Articles XII-XV
- Table 1.1 Acquisition of the Public Domain
1781-1867
-
http://books.google.com/books?id=mNQ1AAAAIAAJ&pg=PA185&lpg=PA185&dq=34th+parallel+wilmot&source=web&ots=6E2_o5IEwy&sig=bQFK83qaH3FNzW71eSBq-GpwJ-c&hl=en&sa=X&oi=book_result&resnum=1&ct=result#PPA191,M1
Quarterly of the Texas State Historical Association, January
1904