Data sources

Where the numbers come from

National and state results for every election (1789 onwards) come from the election summary tables of The American Presidency Project at the University of California, Santa Barbara (Gerhard Peters and John T. Woolley).

County, parish, town and district results for 2012, 2016, 2020 and 2024 come from the official state documents (statements of vote, canvass reports and certified results) that The American Presidency Project links for each state. Each state page links the exact document it was read from.

County results for states and years without a certified county table come from two datasets: the MIT Election Data and Science Lab county returns for 2000–2016 (compiled from official state records), and for 2020 and 2024 county tallies compiled by Tony McGovern from news-media results (US_County_Level_Election_Results_08-24). The 2020 and 2024 tallies are labelled “Media count” because they are not certified documents. A state is used only when its county totals for both main tickets are within 0.5% of the official statewide totals.

The date each state’s governor signed its Certificate of Ascertainment, where it could be read reliably, comes from the certificates linked by the same project.

Senate, House, governors and primaries

Results for U.S. Senate (from 1976), U.S. House (1976–1982 and from 1998), governor (from 1996) and presidential primaries and caucuses (from 2000) come from FiveThirtyEight’s election-results data, which compiles official state and federal sources; each race page links the source for that race. County maps for the 2024 Senate races use the MIT Election Data and Science Lab’s official 2024 returns. U.S. territories are not included.

Members of Congress and presidents

Every member of Congress since 1789, every president and vice president, their terms and party, come from the public-domain congress-legislators project. Official portraits are loaded from the public-domain unitedstates/images collection.

How the documents were read

Text-layer PDFs were read with two independent extraction tools that had to agree. Scanned pages were read by several OCR engines and a number was accepted only when two engines read the same digits; otherwise the cell was left blank and flagged. Every state document was checked against the summary table, and county rows were checked to add up to the statewide totals. Where a document did not match, the page says so and shows the summary figures instead.

What is not here

This site covers presidential races only. Senate, House, governor and local races are not included. County figures are available only where a state’s own document breaks results down that way.

Map boundaries

State and county outlines are derived from U.S. Census Bureau cartographic boundary files (public domain).

Spotted an error? Tell us.