OpenStates

OpenStates tracks legislation across all 50 US state legislatures, plus DC and the territories, and normalises it into one consistent structure. That gives you bills, their full action histories, sponsoring legislators, roll-call votes, and committees, all in the same shape no matter which state produced them, which spares you the misery of reconciling 50 different websites and formats by hand. It updates continuously as bills are filed and votes are recorded.

There are two ways in. A version 3 REST API, free but requiring a key and rate-limited, is ideal for targeted lookups and staying current, while bulk CSV and JSON downloads per state and session are the better choice when you want to ingest a whole history at once. The open-source scrapers that feed it are public too, so you can see exactly how any field is derived. For RAG, the bulk exports build the corpus and the API keeps it fresh.

It suits civic-tech and policy work: a legislative-tracking assistant, a tool that answers what a given state is doing about some issue, or an analysis pipeline that follows bills through committee. The uniform schema makes cross-state comparison genuinely practical rather than a research project in itself.

The licensing is about as friendly as it gets. The data is CC0, a full public-domain dedication with no restrictions, and the code is MIT, so you can build commercially without a second thought. The real caveats are coverage and content: historical depth varies by state, the API's rate limits mean heavy work belongs in the downloads, and bill full text sometimes links out to the state's own site rather than sitting inside the record.

OpenStates covers states only. For the federal picture, pair it with GovInfo and the Congress.gov API; for another angle on state data, LegiScan covers similar ground.