Append County, Congressional & State Legislative Districts to Illinois Addresses

Free browser tool for Illinois address lists: add county, county-equivalent FIPS, congressional district, state senate and house/assembly districts, plus timezone — in one pass, powered by official Census Bureau data.

How it works

  1. Open GeoFlow
  2. Paste your addresses (one per line) or upload a CSV and pick the address column
  3. Click Run — each address is matched against the free U.S. Census Bureau Geocoder
  4. Download the enriched CSV

Real example — 207 N STATE ST, SPRINGFIELD, IL, 62702

Input addressCountyCongressionalState Senate (SLDU)House/Assembly (SLDL)Timezone
207 N STATE ST, SPRINGFIELD, IL, 62702Sangamon County (17167)1713 — Congressional District 1317048 — State Senate District 4817096 — State House District 96

Actual output from the live Census Geocoder for 207 N STATE ST, SPRINGFIELD, IL, 62702.

Illinois facts

Try it free

Open GeoFlow — free up to 100 addresses per run

Data source: U.S. Census Bureau Geocoder (public domain). Timezone: tz-lookup (MIT).

FAQ

What county is Springfield, Illinois in?

The example above — 207 N STATE ST, SPRINGFIELD, IL, 62702 — falls in Sangamon County (FIPS 17167).

Which congressional district covers Illinois?

Congressional districts are numbered per state; the GEOID is the state FIPS (17) plus the district number. Run any Illinois address through the tool to get its current district, senatorial and house/assembly districts in one pass.

Does this work for the whole state?

Yes — the tool covers all of Illinois. The Census Geocoder needs a street address (PO Boxes return NO_MATCH); misspellings and wrong ZIPs are usually auto-corrected.

Is it free?

Yes — up to 100 addresses per run on the free plan, powered by the free official Census Geocoder. A one-time $9 credit pack raises the limit to 1,000 addresses per run.