Data downloads
The district tables behind this site, free and without an account, as CSV files that open in any spreadsheet. Both use the current lines: the 119th Congress and the Illinois General Assembly’s 2024 districts.
District overlaps
Every pair of a U.S. House district and an Illinois Senate or House district that share residents, with how many people they share at the 2020 Census and what share that is of each. Counted census block by census block, so the figures are exact, and districts that only touch along a line are not listed.
Download district-overlaps.csv
Source: U.S. Census Bureau, block equivalency files: 119th Congress (cd119) and 2024 state legislative districts (sldu24, sldl24); 2020 Census, redistricting data (PL 94-171), by block. Built 2026-10-26.
Districts' counties and towns
Every district, Congress and state, with each county and each city, village or community it holds all or part of, and how many people lived in that part at the 2020 Census. A town split by a district line appears once for each district, with the people in that district’s part.
Source: U.S. Census Bureau, 2020 Census, 119th Congressional District and 2024 state legislative district tabulation. Retrieved 2026-10-19. This product uses the Census Bureau Data API but is not endorsed or certified by the Census Bureau.
Census figures are public domain. Credit the U.S. Census Bureau if you publish them; credit to this site is welcome but not required.