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Data

Our lab is a clearinghouse for data sets that can fuel studies on elections and how they're conducted. Find election data and research tools produced by us and others.

Data

all datasets
all units
29 results
MIT Election Data and Science Lab
U.S. House of Representatives Precinct-Level Returns 2018
This dataset contains precinct-level returns for US House elections on November 6, 2018.
MIT Election Data and Science Lab
Local Precinct-Level Returns 2018
This dataset contains precinct-level returns for local elections on November 6, 2018.
MIT Election Data and Science Lab
State Precinct-Level Returns 2018
This dataset contains precinct-level returns for state elections on November 6, 2018.
MIT Election Data and Science Lab
Precinct-Level Returns 2018 by Individual State
This dataset contains precinct-level returns, state by state, for local, state and federal elections on November 6, 2018.
MIT Election Data and Science Lab
U.S. Senate Precinct-Level Returns 2018
This dataset contains precinct-level returns for US Senate elections on November 6, 2018.
MIT Election Data and Science Lab
U.S. Senate county-level results 2022
U.S. Senate election results at the county level, 2022. Dataset created by Fernanda Gonzalez, Samuel Baltz, and Charles Stewart III for the MIT Election Data and Science Lab.
MIT Election Data and Science Lab
U.S. Senate Precinct-Level Returns 2020
This dataset contains precinct-level returns for US Senate elections on November 3, 2020.
MIT Election Data and Science Lab
U.S. Senate statewide 1976–2020
This data file contains constituency (state-level) returns for elections to the U.S. Senate from 1976 to 2020.
Federal Elections
by state
General Election
MIT Election Data and Science Lab
State Constituency-Level Returns 2018
This repository contains official constituency (state-level) for the 2018 midterm elections, including data for the U.S. House, U.S. Senate, state offices and county-level returns.
Federal Elections
by state
General Election
MIT Election Data and Science Lab
U.S. President 1976–2020
This data file contains constituency (state-level) returns for elections to the U.S. presidency from 1976 to 2020.
Federal Elections
by state
General Election
Harvard Dataverse
Cast Vote Records: A Database of Ballots from the 2020 U.S. Election
A database of cast vote records from the 2020 U.S. general election, created by downloading publicly available unstandardized cast vote records, standardizing them into a multi-state database, and extensively comparing their totals to certified election results.
Federal Elections
by state
General Election
MIT Election Data and Science Lab
U.S. House 1976–2022
This data file contains constituency (district) returns for elections to the U.S. House of Representatives from 1976 to 2022.
Federal Elections
by district
General Election
MIT Election Data and Science Lab
County Presidential Election Returns 2000-2020
This dataset contains county-level returns for presidential elections from 2000 to 2020.
Federal Elections
by county
General Election
MIT Election Data and Science Lab
U.S. General Elections 2018 - Unofficial Returns
Unofficial returns for the 2018 midterm general elections.
Federal Elections
by county
General Election
MIT Election Data and Science Lab
U.S. Primary Elections 2018
This is a repository for unofficial 2018 primary election returns.
Federal Elections
by county
Primary Election
MIT Election Data and Science Lab
U.S. General Elections 2018 - Analysis Dataset
This repository includes demographic and past election data that can easily be merged with 2018 election returns to analyze the 2018 election.
Federal Elections
by county
General Election
MIT Election Data and Science Lab
State Precinct-Level Returns 2020
This dataset contains precinct-level returns for state elections on November 3, 2020.
Federal Elections
by precinct
General Election
MIT Election Data + Science Lab
Local Precinct-Level Returns 2020
This repository contains precinct-level returns for the local office elections on November 3, 2020.
Federal Elections
by precinct
General Election
MIT Election Data and Science Lab
State Precinct-Level Returns 2018
This repository contains official precinct-level returns for all offices for the 2018 midterm elections. It is incomplete, but will be updated biweekly until completion.
Federal Elections
by precinct
General Election
MIT Election Data and Science Lab
U.S. House of Representatives Precinct-Level Returns 2016
This dataset contains precinct-level returns for elections to the U.S. House of Representatives on November 8, 2016.
Federal Elections
by precinct
General Election
MIT Election Data and Science Lab
U.S. President Precinct-Level Returns 2016
This dataset contains precinct-level returns for elections to the U.S. presidency on November 8, 2016.
Federal Elections
by precinct
General Election
MIT Election Data and Science Lab
Precinct-Level Returns 2020 by Individual State
This dataset contains precinct-level returns, state by state, for state and federal elections on November 3, 2020.
Federal Elections
by precinct
General Election
MIT Election Data and Science Lab
U.S. House of Representatives Precinct-Level Returns 2020
This dataset contains precinct-level returns for US House elections on November 3, 2020.
Federal Elections
by precinct
General Election
MIT Election Data and Science Lab
2024 Precinct-Level Returns
Repository for the results of the 2024 U.S. general election, mostly at the precinct level.
Federal Elections
by precinct
General Election
MIT Election Data and Science Lab
U.S. President Precinct-Level Returns 2020
This dataset contains precinct-level returns for the US President election on November 3, 2020.
Federal Elections
by precinct
General Election
MIT Election Data and Science Lab
U.S. Senate Precinct-Level Returns 2016
This dataset contains precinct-level returns for elections to the U.S. Senate on November 8, 2016.
Federal Elections
by precinct
General Election
MIT Election Data and Science Lab
State Office-Level Returns 2016
This dataset contains office-level returns for state elections on November 8, 2016.
State Elections
by state
General Election
MIT Election Data and Science Lab
State Precinct-Level Returns 2016
This dataset contains precinct-level returns for state elections on November 8, 2016.
State Elections
by precinct
General Election
MIT Election Data and Science Lab
Local Precinct-Level Returns 2016
This dataset contains precinct-level returns for local elections on November 8, 2016.
Local Elections
by precinct
General Election

Tools + Resources

Software tools

Software tools developed by MEDSL
MEDSL GitHub
This is our GitHub repository where you can find software tools for working with elections data.

Other data sources

This is a list of open data sources recommended by MEDSL.
2010 Voting Districts Codes
National and state files containing codes for Voting Districts are available for download from the U.S. Census Bureau. Voting Districts were not provided by every state and are therefore not available for every state.
A New Nation Votes
This is a searchable collection of election returns from the earliest years of American democracy.
Constituency-Level Elections Archive (CLEA)
The Constituency-Level Elections Archive (CLEA) is a repository of detailed election results at the constituency level for lower house legislative elections from around the world—including the U.S.
Daily Kos Elections' datasets
The ultimate guide to Daily Kos Elections datasets
Dave Leip’s Atlas of U.S. Presidential Elections
This is a resource for U.S. Presidential Election results and other types of election data.
Election Administration and Voting Survey (EAVS)
This is the biennial Election Administration and Voting Survey (EAVS) which collects state-by-state data on the administration of federal elections. It is conducted by the Election Assistance Commission.
Election Geodata
This github provices precinct shapes (and vote results) for U.S. elections past, present, and future.
Federal Voting Assistance Program
FVAP's reports and surveys provide unique insight into UOCAVA voting.
Harvard Election Data Archive
This archive contains data on election results, voting behavior, and electoral politics, with particular focus on the United States.
Klarnerpolitics Dataverse
Harvard Dataverse collection by Carl Klarner with useful data and tools, including state legislative election returns from 1967 to 2012.
Mapping Early American Elections
This project offers a window into the formative era of American politics by producing interactive maps and visualizations of Congressional and state legislative elections from 1787 to 1825.
MEDSL Hosted Election Science Data
This Dataverse contains data that is collected by affiliates and external scholars that MEDSL is hosting and archiving.
MEDSL New Initiatives Grants Dataverse
This dataverse contains the datasets produced by the New Intitiatives Grants Program sponsored by MEDSL and the Hewlett Foundation.
Metric Geometry and Gerrymandering Group
The MGGG Redistricting Lab studies applications of geometry and computing to U.S. redistricting, and builds open-source tools and resources that create public access and analytical power for better understanding districts and their consequences.
OpenElections
OpenElections is working to create the first free, comprehensive, standardized, linked set of election data for the United States, including federal and statewide offices.
PlanScore
PlanScore presents a comprehensive historical database of partisan gerrymandering.
Princeton Gerrymandering Project
This project researches gerrymandering across the states.
Quantifying Gerrymandering
A nonpartisan research group centered @ Duke Math and producing data and analysis on redistricting in the U.S.
Redistricting Data Hub
A portal to access redistricting data, tools, training, and educational resources.
Stephen Pettigrew's 2018 County Returns
November 2018 county-level election returns for US Senate, US House, and governor elections in each state. Also state legislative and local results in many states.
Survey of the Performance of American Elections (SPAE)
This is a survey conducted in conjunction with the Elections Performance Index which gauges the quality of the election experience in the U.S.
The United States Election Project
This is a source for time-series voter turnout data at the national and state levels. The site also includes information on redistircting and voter lists.
Voting Information Project
The Voting Information Project (VIP) works with states to provide official information to voters about where to vote and what’s on their ballots.