Public Law (P.L.) 94-171, enacted by Congress in December 1975, requires the Census Bureau to provide states the opportunity to identify the small area geography for which they need data in order to conduct legislative redistricting. The law also requires the U.S. Census Bureau to furnish tabulations of population to each state, including for those small areas the states have identified, within one year of Census day.
Since the first Census Redistricting Data Program, conducted as part of the 1980 census, the U.S. Census Bureau has included summaries for the major race groups specified by the Statistical Programs and Standards Office of the U.S. Office of Management and Budget (OMB) in Directive 15 (as issued in 1977 and revised in 1997). Originally, the tabulation groups included White, Black, American Indian/Alaska Native, and Asian/Pacific Islander, plus “some other race.” These race data were also cross-tabulated by Hispanic/Non-Hispanic origin. At the request of the state legislatures and the Department of Justice, for the 1990 Census Redistricting Data Program, voting age (18 years old and over) was added to the cross-tabulation of race and Hispanic origin. For the 2000 Census, these categories were revised to the current categories used today.
The 2020 Census Redistricting Data (P.L. 94-171) Summary Files in the Legacy Format were posted for FTP download, by state, on August 12, 2021 and released on data.census.gov with the full redistricting toolkit on September 16, 2021. Both releases contained the same data, only the format was different.
The summary file tables include:
The 2020 Census Redistricting Data (P.L. 94-171) Summary File data are available for all 50 states, the District of Columbia, and the Commonwealth of Puerto Rico through data.census.gov and FTP download (in the Legacy Format).
The 2020 Census State Redistricting Data (P.L. 94-171) Summary File Technical Documentation is available in English, and in Spanish specifically for Puerto Rico. The 2020 Census National Redistricting Data (P.L. 94-171) Summary File Technical Documentation is available in English only. Links to the Technical Documentation are provided below.
Legacy Format Support Materials are provided to help data users work with the legacy format summary files. These materials include header records for each of the data segments in the summary file, Microsoft Access shells, an instructional guide and video tutorial that provide step-by-step instructions on how to download the legacy format data and import the data into the Microsoft Access Shells, and SAS and R statistical software import scripts. Links to these support materials are provided below.
The Census Bureau published a Federal Register Notice on the Final 2020 Census Residence Criteria and Residence Situations on February 8, 2018. In the Notice, the Census Bureau stated we will continue the practice of counting prisoners at the correctional facility, to ensure that the concept of usual residence is interpreted and applied consistent with the intent of the Census Act of 1790. The Notice also stated the Census Bureau recognizes that some states have decided, or may decide in the future, to ‘move’ their group quarters (GQ) population (e.g. student, military, and prisoner population) to an alternate address for the purpose of redistricting. To assist those states, the Census Bureau is offering the use of a geocoding service. This service was updated with 2020 Census geographic data in January 2021, to assist states with their goals of reallocating GQ population for legislative redistricting.
In declarations filed in the case of Ohio v. Raimondo, the U.S. Census Bureau made clear that we could provide a legacy format redistricting data summary file to all states by mid-to-late August 2021, now realized as August 12. We also met our commitment to provide the full redistricting data toolkit by Sept. 30, 2021, with delivery on Sept. 16, 2021.