United States Census
The United States Census is a decennial survey operated by the U.S. Census Bureau to establish demographic information about the nation's population.
Design
Geographies
The census publishes data by several geographic levels:
- states
- counties
- tracts
- demographically and economically homogeneous with a population of around 4,000
- usually follow visible features like rivers
- reviewed every decade for subdivision, but generally tracts can be tracked over time
- block groups
- usually between 250 and 550 housing units
- blocks
- usually follow city blocks
- change every decade, cannot be tracked
Frequency
The census is conducted every 10 years.
History
The first censuses in the United States were administered by U.S. marshalls. The Census Office was established in 1840 to centralize this administration.