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About Our Data

Learn more about the data hosted on the Redistricting Data Hub

Types of Data

Select each data type to read an in-depth description.

Precinct Boundary and Election Results
Precinct level election results merged with precinct boundaries from 2016, 2018, and 2020 were collected by our data partners. We peer reviewed these files as part of our Partner Data Validation effort, and provided detailed reports for each validated dataset. The Redistricting Data Hub team is working on creating 2022 files and making them publicly available.
Voter Files
Voter File data aggregated to census blocks and other geographies are available for all states. This data was purchased by the Redistricting Data Hub from L2, a national voter file vendor.
Incumbent Addresses
The 2020 incumbent address data gathered by Dr. Carl Klarner provides information about current incumbents, including their district number, party registration, gender, race and address. Users will need to request permission to download this data.
Population Projections
HaystaqDNA produced 2020 – 2030 population projections aggregated to the 2010 and 2020 census block and block group levels split into P1 and P2 fields of the PL redistricting file. They are available in CSV and SHP formats.
PL 94-171
The PL 94-171 dataset is the Redistricting Data File created by the U.S. Census Bureau for use by the states in redistricting based on the decennial census. In addition to tabulating the data, our team merged the census data with geographic information, so that it is ready to use in standard mapping softwares.
There are states that have a requirement for modifying the PL 94-171 data prior to redistricting, we maintain a references to those states’ constitutions, statutes, or other rules governing redistricting.
We have formatted a list of the fields and descriptions found in the PL 94-171 dataset found in the 2020 Census State Redistricting Data (Public Law 94-171) Summary File Technical Documentation
Legislative Boundaries
Legislative boundary files for 2011 to the present are re-hosted from All About Redistricting for each state. Legislative boundary files for 2021 and beyond are collected directly from state sources by the Redistricting Data Hub team.
American Community Survey (ACS)
Select fields from the American Community Survey 5-year estimates are available for 2010 to 2021 at the block group, census tract, county, and state level geographies in SHP and CSV format where applicable. The ACS collects a wide range of data, and on our site we host population totals by race and estimates for language spoken at home (not available at the block group level). For more information on field names, see the metadata of your desired dataset.
Citizen Voting Age Population (CVAP)
CVAP Special Tabulation data available for 2010-2021 at the block group, census tract, county, and state level in both SHP and CSV format. 2016-2021 CVAP data is also available at the 2020 block level. Additional CVAP data is available at the Place and MCD (where relevant) for 2018-2021, and SLDU, SLDL, and Congressional Districts level for 2018-2020. Fields were modified to match OMB race categories as used in voting rights analysis. The CVAP data contains estimates by race (for Non-Hispanic/Latino) for total population (not available at the block group or tract levels), voting age population (not available at the block group or tract levels), citizen voting age population, and citizen population. For more information on field names, see the metadata of your desired dataset.
TIGER Boundary Files
Boundary shapefiles are available at several geographies within a state, including blocks, block groups, census tracts, counties, or the entire state. For some states, this may also include 2020 Zip Code Tabulated Areas ZCTAs, American Indian, Alaska Native and Native Hawaiian AIANNH boundaries boundaries and Voting Tabulation Districts VTDs.
Community of Interest (COI) maps
We collected community of interest maps submitted to legislative and congressional redistricting bodies and organizations during the 2021 redistricting cycle. We collected over 10,000 maps in 38 states, and have begun cataloging and uploading them to the Harvard dataverse.
Public Testimony Data
An important part of the redistricting process is public input. To varying degrees, redistricting bodies provide access to the public to share their views, whether that be on the goals of redistricting, the boundaries of proposed maps, the process itself, or something else. This input may be given in a letter, an email, on a website, or in person.
Specialized Data
Data available for download that were created by request. We are continually uploading new data, but you can request that we prioritize creating and rehosting certain datasets. Request a dataset you need for redistricting.
Official adjusted state redistricting datasets
Several states adjust the census data for congressional and/or legislative redistricting purposes, typically to reallocate incarcerated individuals to their last known address. We obtained and rehosted official adjusted datasets in all states but Rhode Island. We have also produced reports that outline the differences between unadjusted and adjusted data at various levels of geography.
Counterfactual Prisoner Adjusted Redistricting Data
Download 2020 Counterfactual Prisoner Adjusted Redistricting Data in 32 States produced by Dr. Rory Kramer and Dr. Brianna Remster of Villanova University. Use these files to understand how prison gerrymandering affects the population in states that do not adjust their census data for redistricting.

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Voting Rights Data

Data that we host that is also useful for voting rights advocacy and election protection

Partner Data Validation

Learn more about how we ensured that the Precinct Boundaries and Election Results files from our data partners were accurate and reproducible

Census Data

Learn more about the decennial census and how to use this data in redistricting

Our Process

Partner Validation

The Partner Data Validation project was an effort by our Data Analysts to peer-review the files we re-host from our Data Partners, who took on the task of collecting and making Precinct Boundaries joined with Election Results publicly available for redistricting in 2020. In looking at the data being collected, the RDH identified six criteria that we believe encompass most issues that may arise with these data. For each state and data partner, the report we released describes in detail what we found for each of these criteria.

We did this because data is critical to court cases. Finding an error that could discredit the dataset can be debilitating and lead to the failure of an argument or defense in court. Additionally, the reports created highlight the benefits and drawbacks of a given partner dataset.


We used Python and the SciPy ecosystem (NumPy, Pandas, GeoPandas, MatPlotLib) to carry out the majority of our validation work. At a high level, our process began by locating Election Results and Precinct Boundaries datasets, cleaning and merging Election Results to Precinct Boundaries, and then comparing the resulting Precinct Boundaries and Election Results file to the equivalent files produced by our Data Partners.

Our API script is available on our GitHub, in order for the script to retrieve data you must be a designated API user. Request access to our API

For more information about our processes and to view our source code, visit our GitHub

Do you need data that isn’t already hosted by the Redistricting Data Hub?

If you need a redistricting dataset we don’t have, let us know what you need and why

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How to Use our Data

Data in the Redistricting Process

Read our Redistricting Readiness Checklist to learn how to use this data in the redistricting process

Redistricting Process

Visit All About Redistricting to learn more about the rules, criteria, and litigation in each state. The website has information about the redistricting process in each state, including the timing, whether and how public input is incorporated, and criteria. The website is a great resource to consult before using our data to draw maps!

Draw or Analyze a Map

Use our Choose Your Own Mapping Tool to find the right software to draw a Community of Interest or District Map


All of the information you need about a given dataset will be included in the metadata, including column/variable names, methods and processing decisions, sources, dates when the data was retrieved, and any other valuable information about the file. If you have a specific question, please reach out to us!

Access Our Data

There are two ways to access data: create a free account and download individual datasets or register as an API user and download multiple datasets at once


Sign up for a free account to download data

Download data for your state

Browse the data available for each state and download datasets individually


Request access to use our Application Programming Interface (API) to download multiple datasets at once

Ask us a question

Our help desk team can answer your questions about our data and the redistricting process. Send them a message and they will respond within one business day!

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