Data sources and licences

USAspending.gov API v2

U.S. Department of the Treasury, Bureau of the Fiscal Service. api.usaspending.gov, no key. Endpoints used: search/spending_over_time (national and state monthly series by award type), search/spending_by_geography (county and district obligations, population), search/spending_by_category (recipient, awarding agency, awarding sub-agency, NAICS, assistance listing rankings and cross-tabulations), search/spending_by_award (new awards of $1M or more), recipient/{id} (parent and business categories for the largest recipients) and awards/last_updated (data date). Licence: in USAspending's words, the data "is available for public use under the Creative Commons CC0 Public Domain Dedication license." Updated nightly by Treasury; this site last used data loaded 30 Sep 2026.

Suggested citation, per USAspending: "USAspending.gov, U.S. Department of Treasury, Bureau of the Fiscal Service. Accessed 30 Sep 2026."

U.S. Census Bureau

Vintage 2025 population estimates for states and counties (Population Estimates Program, CSV file, keyless); 2024 cartographic boundary files at 1:20,000,000 for states, counties and 119th-Congress districts, plus the 2021 county file for Connecticut's former counties; the 2020 congressional district to county relationship file. US government works, public domain. Annual.

Not used

USAspending's executive compensation fields, sub-award and individual-recipient records, and the Census API (the site reads published files, not the API).