Decennial Census

Historic Snapshot of the Nation

The official U.S. Census is described in Article I, Section 2 of the Constitution of the United States. It calls for an actual enumeration of the people every ten years, to be used for apportionment of seats in the House of Representatives among the states. The first official Census was conducted in 1790 under Thomas Jefferson, who was the Secretary of State. That census, taken by U.S. marshals on horseback, counted 3.9 million inhabitants. Since that time, the decennial Census has been conducted every ten years, generally on April 1 in years ending in a zero.

Besides providing the basis for congressional redistricting, Census data are used in many other ways. Since 1975, the Census Bureau has had responsibility to produce small-area population data needed to redraw state legislative and congressional districts. Other important uses of Census data include the distribution of funds for government programs such as Medicaid; planning the right locations for schools, roads, and other public facilities; helping real estate agents and potential residents learn about a neighborhood; and identifying trends over time that can help predict future needs. Most Census data are available for many levels of geography, including states, counties, cities and towns, ZIP Code Tabulation Areas, census tracts, blocks, and much more.




About the 2010 Census

The 2010 Census represented the most massive participation movement ever witnessed in our country. Approximately 74 percent of the households returned their census forms by mail; the remaining households were counted by census workers walking neighborhoods throughout the United States. National and state population totals from the 2010 Census were released on December 21, 2010. Redistricting data, which include additional state, county and local counts, was released starting in February 2011.

For the 2000 Census, additional questions were asked of a sample of persons and housing units (generally 1 in 6 households) on topics such as income, education, place of birth and more. Information on those topics are now available as part of the American Community Survey.

Census 2010

What We Ask

For the 2010 Census, 10 questions were asked of every person and housing unit in the United States. Information is available on:

  • Age
  • Hispanic or Latino origin
  • Household relationship
  • Race
  
  • Sex
  • Tenure (whether the home is owned or rented)
  • Vacancy characteristics

Understanding the Results

The results from the 2010 Census are available in a number of datasets in American FactFinder:

  • 2010 Census Redistricting Data (Public Law 94-171) Summary File - used for congressional and state redistricting. - get data »
  • 2010 Census Demographic Profile - population and housing unit counts and characteristics such as age, race, Hispanic or Latino origin, relationship to householder, household size, group quarters population, housing unit occupancy status, whether a unit is owner- or renter-occupied, and more, summarized in one table. - get data »
  • 2010 Census Summary File 1 (SF 1) - 333 detailed tables providing data on age, sex, households, families, relationship to householder, housing units, detailed race and Hispanic or Latino origin groups, and the population in group quarters. - get data »
  • 2010 Census Summary File 2 (SF 2) - 71 tables providing population and housing characteristics iterated for up to 330 detailed race and Hispanic or Latino categories, and American Indian and Alaska Native tribes/tribal groupings, subject to a population threshold. - get data »

Other decennial data sets:

  • American Indian and Alaska Native Summary File (AIANSF) - 71 tables providing population and housing characteristics population and housing characteristics iterated for 1,570 American Indian and Alaska Native tribes/tribal groupings, subject to a population threshold. - (to be released December 2012)
  • Congressional District Summary File (113th Congress) - provides the Summary File 1 tables retabulated for Congressional districts redrawn following the 2010 Census. (Summary File 1 provides data for the 111th Congress)
  • State Legislative District Summary File - Summary File 1 retabulated with state legislative districts redrawn following the 2010 Census.
Source: U.S. Census Bureau   |   American FactFinder