How to find the congressional and state legislative districts for an address
Geocode the address to latitude and longitude, then check which boundaries contain that point. Boundary Atlas does the second step for every level at once: city, county, ZIP, congressional district, state senate and state house districts and voting precinct, under the maps in force for November 3, 2026. For one address, use the free lookup page; for many, let an agent loop through them.
Who this is for
- Anyone checking their own districts
- Advocacy groups and campaigns
- CRMs that need district fields
Ask your agent
With Boundary Atlas added to Claude, ChatGPT, Cursor or Codex (free, no key; how):
For each address in this list, find its congressional district, state senate and state house districts and county using Boundary Atlas. Geocode with the free Census Geocoder first.
Step by step
- One address. Use the lookup page: type the address and read the cards.
- Geocode. Many addresses: the free U.S. Census batch geocoder takes up to 10,000 per file and returns latitude and longitude.
- Locate. Call locate_point(lat, lon) for each point. It returns every containing area, with source and vintage. Points within ~1 km of a gap snap to the nearest shape and say so (approximate=true).
- Store the IDs. Keep the IDs (e.g. us:congressional_district:1707) rather than names; they're stable and join to everything else in the atlas.
Live example
233 S Wacker Dr, Chicago (Willis Tower), at 41.8786, -87.6362:
| Level | Result |
|---|---|
| City or town | Chicago |
| County | Cook County |
| ZIP code | 60606 |
| Congressional district | Illinois's 7th congressional district (IL-07) |
| State senate district | State Senate District 5 |
| State house district | State House District 9 |
| Voting precinct | 42014 |
| State | Illinois |
| Mayor | Brandon Johnson |
| U.S. Representative | Danny K. Davis (D) |
| U.S. Senator | Richard J. Durbin (D) |
| U.S. Senator | Tammy Duckworth (D) |
| State Senator | Lakesia Collins (Democratic) |
| State Representative | Yolonda Morris (Democratic) |
| City website | chi.gov |
| City council | Chicago City Council |
| County website | www.cookcountyil.gov |
locate_point(lat=41.8786, lon=-87.6362)
Things to know
- This gives districts, not the names of the people elected in them.
- Precincts change between elections; check vintage, and confirm polling places with the county.
Questions
What congressional district is my address in?
Use the free lookup at /lookup, or ask an agent with Boundary Atlas to geocode the address and call locate_point.
More guides
- How to convert ZIP code data to counties (or cities, or districts)
- How to list the ZIP codes in a city, county or congressional district
- How to assign leads and accounts to sales territories by city, county or district
- How to map election results by precinct
- How to match members or supporters to their legislative districts
- How to make a map of your data by county, city or district
- How to tell whether an address is inside city limits
- How to find the federal riding and polling division for a place in Canada
- How to find who represents an address in Congress and the state legislature
- How to find a city's or county's official website and code of ordinances