The Census Bureau produces many publications and data points chronicling the U.S. historical and contemporary demographic, economic, & social development. Population censuses are done every ten years for years ending in zero covering from 1790-2020. Economic and agricultural censuses are now done every five years for years ending in 2 and 7. These publications are available in paper, microfiche, CD-ROM, and the internet. Many Census Bureau publications are accessible through the Libraries online catalog.
The decennial population Census of the United States is constitutionally required for determining congressional representation. After each decennial census, the Census Bureau assigns each state the number of seats it will have in the U.S. House of Representatives for the next ten years. Individual states are given the responsibility of drawing legislative boundaries for congressional districts as well as for state legislative districts. In some states, this process is done by the state legislature (for example, Indiana) and in other states it is done by independent commissions. This process occurred following the 2011 release of state population data from the 2010 Census. It will occur again in 2021 following release of 2020 decennial census population data.
The COVID-19 pandemic has delayed collecting and release of Census data including redistricting data which is now targeted to be delivered to states. between July 1-September 30, 2020. Census Bureau redistricting data will now be delivered to states on Sept. 30, 2021 according to this Census press release from February 12, 2021.
Useful scholarly journal article databases on this subject include:
Most state governments have websites featuring information about their redistricting practices and policies. Examples of general resources on redistricting can be found at the following sites which describe post 2000 and 2010 population census redistricting:
Most U.S. states have redistricting websites, some have more than one.