How to find who represents an address in Congress and the state legislature

Place the address in its districts, then look up who holds each seat. Boundary Atlas does both: its find_officials tool returns the member of the U.S. House, both U.S. senators, and the state senator and state representative for any point, with party, phone and website. Use the free lookup page for one address.

Who this is for

Residents contacting their representatives
Advocacy and constituent services
Journalists

Ask your agent

With Boundary Atlas added to Claude, ChatGPT, Cursor or Codex (free, no key; how):

Who are the members of Congress and state legislators for 233 S Wacker Dr, Chicago? Use Boundary Atlas.

Step by step

One address. Use the lookup page: the officials appear as cards below the districts.
Geocode. Many addresses: the Census batch geocoder, up to 10,000 per file.
Find officials. find_officials(lat, lon) for each point, or find_officials(id=...) for a district, city or ZIP (with shares when the area spans districts).
Contact. Each official has a website and phone; members of Congress also have a contact form.

Live example

233 S Wacker Dr, Chicago:

Office	Name	Party
Mayor	Brandon Johnson
U.S. Representative	Danny K. Davis	Democrat
U.S. Senator	Richard J. Durbin	Democrat
U.S. Senator	Tammy Duckworth	Democrat
State Senator	Lakesia Collins	Democratic
State Representative	Yolonda Morris	Democratic

find_officials(lat=41.8786, lon=-87.6362)

Things to know

Members of Congress listed are those serving until January 3, 2027; in states that redrew for 2026 they were elected under the previous map, and the page says so.
State legislators come from Open States; a few multi-member or renamed districts have no member on record.
Mayors are included for about 1,000 cities (Open States, then Wikidata); city council members aren't yet, but the city's council page is linked where known.

Questions

Who is my representative?

Type your address at /lookup: it shows your member of the U.S. House, your senators and your state legislators.