Methodology

Federal Election Commission (FEC)

Our primary data source. We process FEC bulk data files including candidate filings, committee reports, and individual contributions. This data is updated quarterly with supplemental e-filing data available daily.

https://www.fec.gov/data/browse-data/?tab=bulk-data

U.S. Census Bureau / USPS

We use Census TIGER data and USPS records to map zip codes to congressional districts. This allows users to look up their representatives by entering their zip code.

https://www.census.gov/geographies/mapping-files.html

Congressional Bioguide

Official biographical directory of Congress, used for member photos and basic biographical data.

https://bioguide.congress.gov/

1. Data Ingestion

We download FEC bulk data files (pipe-delimited CSV format) after each quarterly release. These files include candidate master records, committee master records, and individual contribution records.

2. Entity Resolution

Matching donors across records is one of the hardest challenges. We use FEC committee IDs for PACs and combine name, employer, and zip code for individual donors. Some entity resolution errors are inevitable — we err on the side of not merging when uncertain.

3. Industry Classification

We classify donors into industries using the Center for Responsive Politics (CRP) industry coding system. Individual donors are classified based on their reported employer and occupation. PACs are classified based on their registered connected organization.

4. Aggregation

Contribution amounts are aggregated by election cycle. The “total raised” figure includes all individual contributions, PAC contributions, and party committee contributions reported to the FEC. Self-financing by candidates is tracked separately.

5. Money Map Generation

The money map visualization shows the top 20 donors to each official, with node sizes proportional to contribution amounts and edge thickness representing the volume of the relationship. Donor nodes are colored by type (individual, PAC, super PAC, or party committee).

Federal officials only

We currently cover U.S. House and Senate members. State and local officials are not yet included.

Contribution data only

We show direct campaign contributions. Lobbying expenditures, independent expenditures by super PACs (which are not contributed directly to candidates), and dark money are not yet included.

Data lag

FEC data can lag by days to weeks. E-filings are available quickly, but paper filings and bulk data releases are quarterly. We display 'last updated' dates on all pages.

Entity resolution imperfections

Some individual donors may appear as duplicates if they report different name variations or employers across filings. We prioritize accuracy over completeness in merging records.

Zip code to district mapping

Some zip codes span multiple congressional districts. In these cases, we map to the district that contains the largest portion of that zip code's population.