The Decennial Census of Population and Housing is conducted every 10 years as mandated by the Constitution to count every person residing in the United States, including all 50 states, the District of Columbia, Puerto Rico, and the Island Areas. This count is used to determine Congressional representation. Everyone residing in the U.S. must be counted, regardless of age, race, ethnicity, or citizenship status.
The Census has an important impact in many areas:
Census data is crucial because it directly determines how billions of dollars in federal and state funding are allocated annually for community needs like public health, education, and transportation.
The Constitution mandates the census be used to apportion seats in the U.S. House of Representatives and redistrict state legislatures.
Census data defines legislative districts, school assignment areas, and other crucial government functional areas.
The census provides a vital snapshot that helps define the nation. Data on community changes are crucial for planning decisions, such as determining where to place services for the elderly, build new roads and schools, or locate job training centers.
The main purpose of the decennial census is Congressional Apportionment: distributing the 435 seats in the House of Representatives among the 50 states.
A state's apportionment population is calculated by adding its resident population (persons "usually resident" in the state) to the count of overseas U.S. military and federal civilian employees and their dependents allocated to that state.