CRS INSIGHT Prepared for Members and Committees of Congress

INSIGHTi

Congressional District Geography Workbook (119^th Congress): An Interactive Tool for Congressional Users

January 21, 2025

This Insight accompanies the Congressional District Geography Workbook, a Microsoft Excel file that congressional users can download from CRS.gov. The workbook provides information about U.S. House districts as configured in the 119^th Congress (2025-2026).

It supersedes the version published for the 118^th Congress: CRS Insight IN12393, Congressional District Geography Workbook: An Interactive Tool for Congressional Users, by Ben Leubsdorf.

This new Workbook incorporates updated datasets, new categories of geographic areas and features, and revised district boundaries in five states (Alabama, Georgia, Louisiana, New York, and North Carolina).

Workbook Overview and Layout

The Congressional District Geography Workbook contains information about selected geographic areas and features located inside each of the 435 congressional districts across all 50 states. It also includes information for the District of Columbia, Puerto Rico, American Samoa, Guam, Northern Mariana Islands, and U.S. Virgin Islands.

The 20 available categories of geographic areas and features are as follows:

• Airports;

• Chambers of Commerce;

• Counties and equivalent entities, such as Louisiana parishes;

• County Subdivisions, such as townships and Census County Divisions (CCDs);

• Major Sports Venues, including U.S. home arenas and stadiums for MLB, MLS, NBA, NFL, NHL, NWSL, PWHL, and WNBA teams;

• Military Installations;

• Native American Areas, such as reservations;

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• Places, including municipalities such as cities and unincorporated Census Designated Places (CDPs);

• Ports, including port districts that may extend beyond a port’s physical infrastructure;

• Postsecondary Institutions, such as colleges and universities;

• Power Plants;

• Private Schools (elementary and secondary);

• Public Libraries;

• Public Schools (elementary and secondary);

• School Districts;

• Spaceports, including commercial and federal launch and reentry sites;

• State Capitol Buildings;

• State Legislative Districts, both lower chambers (i.e., State House districts) and upper chambers (i.e., State Senate districts);

• Train Stations; and

• ZIP Codes.

A geographic area or feature is associated with a specific congressional district when it is located fully or partly inside that district’s boundaries. An area or feature may be located entirely within a single district or split between two or more districts.

The workbook, when downloaded and opened in Microsoft Excel, contains five sheets that can be accessed via tabs at the bottom of the screen.

• “Workbook Information” contains a table of contents and background information.

• “What’s In Your District” contains a pivot table. Users select a state/territory and a district to generate a list of areas and features in that district. An Export Selection button allows users to quickly copy that list and paste it into a new spreadsheet.

• “Complete Data Table” holds roughly 329,000 rows of data, the information that powers the pivot table. On this screen, area/feature names appear in italics if they are split between two or more districts.

• “Maps” contains guidance on locating district maps.

• “Statistics” contains hyperlinks to Census Bureau statistical profiles for each district on the data.census.gov platform.

The workbook sheets are formatted for ease of use and are password-protected to prevent changes.

CRS can provide Members and staffers with additional analysis and information upon request (e.g., points of interest not included in the Workbook, additional information for some categories, or the extent of overlaps for areas split among more than one district).

Data Sources and Methodology

CRS downloaded data from the sources described below in January 2025, unless otherwise noted. These datasets were the most recent available, though they may have been compiled or updated at different times. The workbook may contain errors, including potential mistakes present in the source datasets.

The Bureau of Transportation Statistics (BTS) provided information about airports, spaceports, and train stations. CRS used the tigris and sf packages in the R statistical programming language to match each

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facility’s longitude and latitude coordinates, as provided by BTS, with a corresponding congressional district. (CRS used the same district-matching procedure for several other categories as well.) The Airport list comprises major Part 139 airports certified by the Federal Aviation Administration (FAA); a full list of public-use airports eligible for federal funding is available in the FAA’s National Plan of Integrated Airport Systems. The Train Station list excludes Amtrak-operated bus stops. The Spaceport list includes commercial and federal launch and reentry sites. Because these facilities are all represented by point locations, their district assignments may not capture the full extent of their physical footprints

The Census Bureau provided information about counties, county subdivisions, Native American areas, places, and school districts. Its Congressional District Relationship Files contain crosswalks between 119^th Congress congressional districts and geographic areas used in the 2020 census.

CRS matched state legislative districts in the 50 states, the District of Columbia, and Puerto Rico to congressional districts using the Census Bureau’s 2024 State Legislative Block Equivalency Files (BEFs) and 119^th Congress BEFs. Relationships between state legislative and congressional districts were established based on shared census blocks, with split blocks assigned to all matching districts.

CRS in December 2024 and January 2025 matched five-digit ZIP codes to congressional districts using GIS software and data from Esri. These include ZIP codes that represent single delivery points as well as approximated delivery areas, as of 2023. This should not be taken as an official or definitive placement of ZIP codes in congressional districts, and slight differences in methodology may result in different results.

The Department of Defense provided information directly to CRS in November 2024 about military installations in each congressional district. The source dataset excludes some facilities due to national security concerns as well as relatively small facilities, including many National Guard and Reserve sites. It also excludes U.S. Coast Guard facilities, which fall under the Department of Homeland Security.

The Energy Information Administration (EIA) provided information about power plants. The dataset contains all operable electric generating facilities in the 50 states, the District of Columbia, and Puerto Rico with nameplate capacity of at least 1 megawatt. CRS matched each power plant’s longitude and latitude coordinates, as provided by EIA, with a corresponding congressional district. Plant names are accompanied by information on that facility’s city location and energy source(s).

The major sports venue category includes all U.S. home arenas and stadiums used by professional baseball (MLB), basketball (NBA and WNBA), football (NFL), hockey (NHL and PWHL), and soccer (MLS and NWSL) teams as well as additional facilities with seating capacity of 30,000 or more. Stadium locations provided by the FAA, as well as CRS-geocoded addresses for smaller facilities, were matched with corresponding congressional districts. Because these facilities are represented by point locations, their district assignments may not capture the full extent of their physical footprints.

The Institute of Museum and Library Services (IMLS) provided information about public libraries. CRS relied on IMLS’s 118^th Congress district assignments for public libraries in most states. For public libraries in Alabama, Georgia, Louisiana, New York, and North Carolina, CRS matched each location’s longitude and latitude coordinates, as provided by IMLS, with a corresponding congressional district. Each library’s name is followed by its system name in parentheses, unless the two names are identical.

The Internal Revenue Service’s Exempt Organizations Business Master File Extract contained address information for nearly 6,700 chambers of commerce (tax-exempt 501(c)6 organizations with classification code 3). CRS geocoded each address to generate longitude and latitude coordinates, then matched each point with a corresponding congressional district. Some addresses that could not be geocoded were instead matched based on states and ZIP codes associated with a single congressional district. District assignments were not available for roughly 15% of these organizations (most listing P.O. boxes as addresses); they were excluded from the final list.

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The National Center for Education Statistics (NCES) provided information about public elementary and secondary schools, private elementary and secondary schools, and postsecondary institutions via its Education Demographic and Geographic Estimates (EDGE) program. CRS relied on NCES’s 118^th Congress district assignments for public schools and postsecondary institutions in most states. For public schools and postsecondary institutions in Alabama, Georgia, Louisiana, New York, and North Carolina, as well as all private schools, CRS matched each location’s longitude and latitude coordinates, as provided by NCES, with a corresponding congressional district. The most recent files available were 2023-2024 data for public and postsecondary schools and 2021-2022 data for private schools. The private school dataset does not include schools in U.S. territories. Because postsecondary institutions are represented by point locations, congressional-district assignments may not capture the full extent of a college or university’s campus. The postsecondary institution category may include administrative offices that are not necessarily associated with student populations.

The U.S. Army Corps of Engineers provided information directly to CRS in December 2024 about ports in each district, including ports on rivers and lakes as well as seaports. This list includes port statistical areas, which are defined in legislation and may extend well beyond the port’s physical infrastructure.

The U.S. Geological Survey (USGS) provided information about state capitol buildings. CRS matched each building’s longitude and latitude coordinates, as provided by USGS, with a corresponding congressional district. This list includes legislature buildings in territories and the District of Columbia.

Updates

This product may be updated in 2025 and 2026 to incorporate changes to its underlying datasets. Any updates will be noted in this space so users are aware when a new version is available to download.

CRS plans to publish a new version of the Congressional District Geography Workbook in 2027 to incorporate any changes to congressional-district boundaries for the 120^th Congress (2027-2028), as well as updates to source datasets.

Author Information

Ben Leubsdorf Senior Research Librarian

Disclaimer

This document was prepared by the Congressional Research Service (CRS). CRS serves as nonpartisan shared staff to congressional committees and Members of Congress. It operates solely at the behest of and under the direction of Congress. Information in a CRS Report should not be relied upon for purposes other than public understanding of information that has been provided by CRS to Members of Congress in connection with CRS’s institutional role. CRS Reports, as a work of the United States Government, are not subject to copyright protection in the United States. Any CRS Report may be reproduced and distributed in its entirety without permission from CRS. However, as a CRS Report may include copyrighted images or material from a third party, you may need to obtain the permission of the copyright holder if you wish to copy or otherwise use copyrighted material.