County Maps US

Hamilton County, Illinois

A county in Illinois, ranked 89 of 102 by population.

CountyFIPS 17065

Within Illinois
Hamilton County, highlighted, with the areas around it. Boundaries generalised from the 2025 Census cartographic boundary file; neighbour fills carry no data. The dot marks McLeansboro, the county seat, located via the 2025 Census Gazetteer.

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Population
7,859
-137 (-1.7%) since 2020
Land area
434.7
square miles. A further 0.3% of the total area is water
Population density
18.1
people per square mile, computed rather than published
County seat
McLeansboro
Seat of county government.
Established
1821
204 years ago
Largest city
McLeansboro city
Population 2,585.

Sources: US Census Bureau, Population Estimates Program, Vintage 2025 Population Estimates, released 26 March 2026; US Census Bureau, Gazetteer Files, 2025 Gazetteer Files, released 10 September 2025; Wikidata (CC0), Wikidata. Retrieved 30 August 2026.

Satellite view

Aerial imagery of Hamilton County with its boundary drawn on top. A map shows you the shape; this shows you what is inside it, and which side of the line a place falls on.

Aerial view of Hamilton County, Illinois from the USGS National Map, with its boundary outlined
Imagery: USGS National Map, USGS Imagery Only, public domain, requested from USGS by your browser when you reach this point on the page, at 626 by 800 pixels. The boundary is the 2025 Census cartographic boundary file, reprojected to Web Mercator to match the imagery. You can also open the USGS National Map viewer.

Where Hamilton County ranks

Position among the 102 counties of Illinois, and among all 3,144 US counties and county-equivalents. Computed from the figures on this page.

MeasureValueIn IllinoisNationally
Population7,85989th of 1022,583rd of 3,144
Land area434.7 sq mi66th of 1022,333rd of 3,144
Population density18.1 per sq mi96th of 1022,304th of 3,144
Median household income$65,74660th of 1021,567th of 3,143

Full data for Hamilton County

Every figure below is attributed to the Census Bureau product it came from, with the vintage of that product.
MeasureValueSource and vintage
Population7,859Vintage 2025 Population Estimates
Population in 20207,996Vintage 2025 Population Estimates
2020 estimates base?7,992Vintage 2025 Population Estimates
Land area434.7 sq mi2025 Gazetteer Files
Water area1.2 sq mi2025 Gazetteer Files
Total area435.9 sq mi2025 Gazetteer Files
Population density?18.1 per sq miComputed: Vintage 2025 estimates divided by 2025 Gazetteer land area
Median household income$65,746American Community Survey 2020-2024 5-Year Estimates
Median home value$113,700American Community Survey 2020-2024 5-Year Estimates
Median age43.9American Community Survey 2020-2024 5-Year Estimates
Households3,387American Community Survey 2020-2024 5-Year Estimates
Housing units3,803American Community Survey 2020-2024 5-Year Estimates

Sources: US Census Bureau, Population Estimates Program, Vintage 2025 Population Estimates, released 26 March 2026; US Census Bureau, Gazetteer Files, 2025 Gazetteer Files, released 10 September 2025; US Census Bureau, American Community Survey, American Community Survey 2020-2024 5-Year Estimates, released 29 January 2026. Population density is computed here, not published: it divides the Vintage 2025 population estimate by the 2025 Gazetteer land area, which are two different Census products. Retrieved 30 August 2026.

How the population changed

The Census Bureau publishes the components behind an estimate, not just the total. For the year to July 2025:

Births minus deaths
-17
85 births, 102 deaths
Net migration
+16
More people moved in than moved out.

Source: US Census Bureau, Population Estimates Program, Vintage 2025 Population Estimates, released 26 March 2026. Retrieved 30 August 2026.

The 6 areas bordering Hamilton County

Ordered by the length of the border actually shared, which the Census Bureau publishes in its county adjacency file and which no other county reference presents.

Bordering areaStateShared borderPopulation
White CountyIllinois24 mi13,250
Saline CountyIllinois18 mi22,772
Wayne CountyIllinois18 mi15,882
Franklin CountyIllinois15 mi36,916
Jefferson CountyIllinois9.1 mi36,147
Gallatin CountyIllinois259 ft4,616

Source: US Census Bureau, County Adjacency File, 2025 County Adjacency File, released 15 September 2025. Retrieved 30 August 2026.

All 102 counties of Illinois

Open the interactive Illinois county map, or jump straight to any of them.

Data on this page last rebuilt 30 August 2026. How these figures are produced.