areas in the United
States are defined by the U.S. Census Bureau
census block groups
of at least
with any census block groups around this core having a density of
at least . Urban areas are delineated without regard to political
boundaries. The census has two distinct categories of urban areas.
have populations of greater than 50,000,
while Urban Clusters
have populations of less than 50,000.
An urbanized area serves as the core of a metropolitan statistical area
while an urban cluster serves as the core of a micropolitan statistical