Congressional District

Congressional districts (CDs) are the 435 areas from which people are elected to the U.S. House of Representatives. After the apportionment Apportionment is the process of dividing up the 435 memberships, or seats, in the House of Representatives among the 50 states. The Census Bureau has a dual responsibility in this connection. It conducts the census at 10-year intervals. At the conclusion of each census, the Census Bureau uses the results for calculating the number of House memberships each state is entitled to have. The latter process is the initial use of the basic results of each census. of congressional seats among the states, based on census population counts, each state is responsible for establishing CDs for the purpose of electing representatives. Each CD is to be as equal in population to all other CDs in the state as practicable.

The CDs in effect at the time of Census 2010 are those of the 111th Congress, whose session began in January 2009. The code "00" is used for states with a single representative. American Samoa, Guam, the Virgin Islands (U.S.), and the District of Columbia are represented in the House of Representatives by a delegate, and Puerto Rico by a resident commissioner, all of whom may not vote on the floor of the House of Representatives, but may vote on legislation as it is considered by committees to which they have been named. In computer-readable data products that display a congressional district field, the two-digit FIPS code "98" is used to identify such representational areas. The Northern Mariana Islands does not have representation in Congress. The FIPS code "99" identifies areas with no representation in Congress.