The Tabula America maps are built from election results, district boundary files, and demographic surveys sourced from the organizations listed below.

Sources

[1] Wikipedia — Election Results
County-level election results compiled by Wikipedia contributors from official state and county reporting bodies. Used for county election returns across presidential, congressional, and gubernatorial races.
Link: wikipedia.org

[2] Redistricter — GeoJSON, Election Results
Precinct and district boundary GeoJSON files with associated election results. Used for district geometry and vote tallies at the precinct and legislative district level across the map layers.
Link: redistricter.com/

[3] Dave’s Redistricting — GeoJSON, Election Results
Congressional and state legislative district boundary files and election data. Used for official district shapefiles and partisan performance metrics across the congressional and state house map layers, including historical district configurations across multiple election cycles.
Link: davesredistricting.org

[4] The New York Times — Election Results
Election night and certified results for 2024 President for states that are not fully available for DRA/Redistricter.
Link: github.com/nytimes/presidential-precinct-map-2024

[5] U.S. Census Bureau — American Community Survey (ACS) — Demographics
ACS 5-Year Estimates provide the demographic backbone of the Tabula America index layers. Used for household income, educational attainment, race and ethnicity, housing, and population data at the tract, county, congressional district, and state levels.
Link: census.gov/programs-surveys/acs

[6] U.S. Census Bureau — Decennial Census — Demographics
Full-population counts from the 2010 and 2020 Decennial Census. Used for redistricting population equality analysis and density calculations.
Link: census.gov