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Illinois by county: Census 2020–2024

Every adult in Illinois, as the Census counts them, county by county and grouped by metro area. Each person is a real combination of traits from the Census's anonymised person records, weighted so every county matches its published tables, with party lean and 2024 turnout modelled and labelled so.

102 places, by metro area / county · Team plan

Every plan can look; creating a population from a state by county or by município needs Team.

What each person has

Age
- 18-2412%
- 25-3417%
- 35-4417%
- 45-5416%
- 55-6416%
- 65-7413%
- and 1 more
Sex
- Man49%
- Woman51%
Race and ethnicity
- White61%
- Black13%
- Hispanic17%
- Asian6%
- Other or more than one race3%
Education
- No high school diploma10%
- High school diploma or GED26%
- Some college or associate's degree29%
- Bachelor's degree22%
- Graduate degree14%
Household income
- Under $25,00010%
- $25,000–49,99913%
- $50,000–74,99913%
- $75,000–99,99913%
- $100,000–149,99920%
- $150,000 or more29%
- and 1 more
Work
- Working61%
- Unemployed, looking for work4%
- Not in the labor force35%
Home
- Lives in an owned home69%
- Lives in a rented home28%
- Lives in group quarters3%
Marital status
- Married49%
- Widowed6%
- Divorced10%
- Separated2%
- Never married33%
Children at home
- No children at home68%
- Children at home32%
Veteran
- Not a veteran95%
- Veteran5%
Born
- Born in the US82%
- Born abroad18%
Health coverage
- Has health coverage92%
- No health coverage8%
Disability
- No disability85%
- Has a disability15%
Citizenship
- US citizen92%
- Not a US citizen8%
Party lean (modelled)
- Democratic-leaning47%
- Republican-leaning36%
- Independent or no lean17%
Voted in 2024 (modelled)
- Voted57%
- Did not vote35%
- Not eligible (not a citizen)8%

County by county

Adults in each county: darker has more. Point at a county for its numbers.

3,0724,089,888adults, on a log scale

Error report

How close these people come to the published figures, and where they fall short.

9,921,459 adults · 506,555 Census records · 102 counties in 13 areas (metro areas and the rest of the state)

Built 2026-10-10 · records illinois-2024-v1

How close the people land on the Census

Each county's records are weighted until they match its American Community Survey tables. The figure is the worst county's largest gap on each table, in percentage points.

Table	Worst county
Sex by age	0.5
Race and ethnicity	0.5
Education	0.5
Household income	0.5
Work	0.2
Owned or rented home	0.2
Citizenship	0.0

A check left out of the fit: veterans

Veteran status was not used in weighting, so it shows how well the weighted people carry traits nobody fitted. Per county, the share of veterans among civilian adults lands a median 0.6 points from the Census's own figure; 95% of counties within 1.9, the worst 3.3.

What drawing a population adds

A population is a sample of these weighted people, so small counties vary from draw to draw. Largest gap per county between the people drawn and the county's records, counties with at least 30 people.

Trait	10,000 people		100,000 people
	Median	95% of counties within	Median	95% of counties within
Race and ethnicity	0.6	2.1	0.3	1.4
Education	2.9	6.2	1.2	4.8
Household income	1.4	3.4	0.7	2.7

Party lean and 2024 turnout (modelled)

No Census record says how anyone votes, so these two traits are modelled. Each person starts from what Cooperative Election Study 2024 respondents like them (race, age, education and sex, in the Census Midwest) said and did, with turnout checked against the voter file. Each county is then calibrated so its people's turnout and Democratic-minus-Republican margin match its 2024 presidential result (MIT Election Lab). Those results count votes for president, so turnout runs a point or so under ballots cast.

Check	Margin	Turnout
Each county against its 2024 result (calibrated)	median 0.0, worst 0.0	median 0.0, worst 0.0
Demographics alone, given only the statewide result	median 37.4, worst 62.3	median 2.7, worst 12.2
The same, with priors that never saw anyone from Illinois	median 37.3, worst 62.4	median 2.5, worst 11.8

Leans against Illinois's own survey respondents

Nothing was fitted to these: the share of each lean among Illinois's adults, as modelled and as the CES's Illinois respondents gave it.

	Democratic	Republican	Neither	Turnout
Model	47%	36%	17%
CES Illinois (n=2,302)	48%	34%	18%
Priors that never saw anyone from Illinois, applied to its 2,268 citizen respondents	41%	41%	18%	59%
CES Illinois, citizens (n=2,268)	49%	35%	17%	59%

The county totals are right by construction: that is what calibration does. The honest test is the people alone, in the table above: given only the statewide result, how far each county's people land from its margin. Counties that vote very differently from people like them elsewhere in the region land furthest; the map shows where.

Within a county, calibration moves everyone's lean by the same factor, so lean by race inside one county is the weakest part. In the smallest counties the Census's five-year estimates carry wide margins, and where more presidential votes were cast than the estimate of citizens, turnout is held at 98%.

Use these traits to include or compare groups. They are not anyone's stated party, and results are never polls of real people.

Every county (102)

County	Area	Adults	Census gap	Veterans (Census / people)	Turnout 2024	Margin: result / demographics alone
Adams	Small towns and rural Illinois	50,176	0.4	8% / 7%	64%	−47 / −4
Alexander	Cape Girardeau	3,835	0.3	9% / 10%	59%	−19 / +8
Bond	St. Louis	13,753	0.3	6% / 7%	59%	−45 / −2
Boone	Rockford	40,580	0.1	6% / 6%	64%	−14 / −0
Brown	Small towns and rural Illinois	5,260	0.5	4% / 7%	47%	−60 / −3
Bureau	Small towns and rural Illinois	26,067	0.3	6% / 7%	62%	−24 / −6
Calhoun	St. Louis	3,469	0.2	10% / 10%	77%	−56 / −9
Carroll	Small towns and rural Illinois	12,817	0.2	9% / 8%	62%	−32 / −7
Cass	Small towns and rural Illinois	9,665	0.3	6% / 7%	62%	−43 / −6
Champaign	Champaign-Urbana	168,878	0.4	4% / 4%	59%	+24 / +11
Christian	Small towns and rural Illinois	27,056	0.2	8% / 7%	58%	−47 / −9
Clark	Small towns and rural Illinois	11,854	0.2	8% / 7%	70%	−51 / −6
Clay	Small towns and rural Illinois	9,941	0.3	9% / 8%	68%	−67 / −10
Clinton	St. Louis	28,974	0.3	9% / 8%	67%	−52 / −3
Coles	Small towns and rural Illinois	38,228	0.2	6% / 6%	57%	−28 / −2
Cook	Chicago-Naperville-Elgin	4,089,888	0.4	3% / 3%	58%	+42 / +22
Crawford	Small towns and rural Illinois	14,765	0.3	8% / 7%	61%	−52 / −5
Cumberland	Small towns and rural Illinois	8,017	0.5	7% / 7%	72%	−62 / −8
DeKalb	Chicago-Naperville-Elgin	78,980	0.2	5% / 6%	63%	+2 / +4
De Witt	Small towns and rural Illinois	12,093	0.2	10% / 8%	65%	−45 / −7
Douglas	Small towns and rural Illinois	14,892	0.3	7% / 6%	58%	−46 / −5
DuPage	Chicago-Naperville-Elgin	723,949	0.2	3% / 4%	70%	+13 / +10
Edgar	Small towns and rural Illinois	13,260	0.3	6% / 7%	60%	−52 / −9
Edwards	Small towns and rural Illinois	4,737	0.4	7% / 8%	70%	−71 / −9
Effingham	Small towns and rural Illinois	26,257	0.3	7% / 8%	74%	−60 / −4
Fayette	Small towns and rural Illinois	16,960	0.2	7% / 8%	57%	−65 / −8
Ford	Champaign-Urbana	10,276	0.2	8% / 7%	65%	−48 / −8
Franklin	Small towns and rural Illinois	29,083	0.2	8% / 8%	61%	−51 / −8
Fulton	Small towns and rural Illinois	26,569	0.2	7% / 8%	61%	−24 / −7
Gallatin	Small towns and rural Illinois	3,833	0.2	6% / 8%	66%	−54 / −11
Greene	Small towns and rural Illinois	9,108	0.1	7% / 8%	67%	−58 / −10
Grundy	Chicago-Naperville-Elgin	40,280	0.3	7% / 7%	67%	−30 / −2
Hamilton	Small towns and rural Illinois	6,185	0.4	8% / 8%	68%	−63 / −6
Hancock	Small towns and rural Illinois	13,646	0.2	7% / 8%	67%	−50 / −7
Hardin	Small towns and rural Illinois	3,072	0.5	9% / 10%	63%	−62 / −12
Henderson	Small towns and rural Illinois	5,048	0.3	9% / 8%	69%	−39 / −11
Henry	Davenport-Moline-Rock Island	38,127	0.2	7% / 7%	66%	−24 / −5
Iroquois	Small towns and rural Illinois	20,746	0.3	7% / 7%	66%	−57 / −9
Jackson	Small towns and rural Illinois	43,070	0.4	5% / 7%	55%	+3 / +7
Jasper	Small towns and rural Illinois	7,111	0.2	6% / 8%	77%	−65 / −7
Jefferson	Small towns and rural Illinois	28,410	0.2	8% / 8%	59%	−48 / −4
Jersey	St. Louis	17,067	0.1	9% / 8%	69%	−50 / −7
Jo Daviess	Small towns and rural Illinois	17,879	0.2	7% / 9%	70%	−17 / −6
Johnson	Small towns and rural Illinois	10,893	0.4	8% / 8%	56%	−58 / −3
Kane	Chicago-Naperville-Elgin	393,691	0.4	4% / 5%	64%	+9 / +7
Kankakee	Kankakee	82,363	0.3	7% / 7%	60%	−21 / +3
Kendall	Chicago-Naperville-Elgin	100,437	0.4	5% / 5%	71%	+2 / +9
Knox	Small towns and rural Illinois	39,139	0.5	7% / 7%	58%	−9 / −4
Lake	Chicago-Naperville-Elgin	547,917	0.2	5% / 5%	64%	+21 / +10
LaSalle	Small towns and rural Illinois	85,694	0.4	8% / 7%	63%	−18 / −6
Lawrence	Small towns and rural Illinois	12,235	0.4	7% / 7%	51%	−56 / −6
Lee	Small towns and rural Illinois	27,214	0.4	6% / 7%	60%	−22 / −5
Livingston	Small towns and rural Illinois	27,763	0.4	7% / 7%	60%	−46 / −7
Logan	Small towns and rural Illinois	22,375	0.4	6% / 7%	57%	−42 / −4
McDonough	Small towns and rural Illinois	22,070	0.3	5% / 6%	55%	−19 / +1
McHenry	Chicago-Naperville-Elgin	241,502	0.2	6% / 6%	71%	−5 / +0
McLean	Bloomington	135,165	0.4	5% / 5%	67%	+5 / +6
Macon	Decatur	78,783	0.2	7% / 7%	59%	−19 / +1
Macoupin	St. Louis	35,214	0.2	8% / 8%	67%	−39 / −8
Madison	St. Louis	207,890	0.2	8% / 8%	65%	−13 / +1
Marion	Small towns and rural Illinois	28,315	0.2	8% / 8%	60%	−49 / −7
Marshall	Peoria	9,269	0.3	9% / 8%	67%	−36 / −10
Mason	Small towns and rural Illinois	10,098	0.4	8% / 8%	63%	−42 / −10
Massac	Paducah	10,910	0.3	8% / 8%	62%	−49 / −4
Menard	Springfield	9,452	0.3	9% / 8%	68%	−41 / −5
Mercer	Davenport-Moline-Rock Island	12,265	0.2	8% / 8%	68%	−27 / −8
Monroe	St. Louis	27,385	0.2	9% / 12%	77%	−36 / −1
Montgomery	Small towns and rural Illinois	22,321	0.4	9% / 8%	59%	−44 / −8
Morgan	Small towns and rural Illinois	26,769	0.3	8% / 7%	55%	−32 / −5
Moultrie	Small towns and rural Illinois	10,792	0.1	6% / 7%	61%	−49 / −8
Ogle	Small towns and rural Illinois	40,065	0.4	9% / 7%	66%	−29 / −5
Peoria	Peoria	136,674	0.2	6% / 6%	60%	+5 / +8
Perry	Small towns and rural Illinois	16,660	0.2	8% / 8%	56%	−52 / −5
Piatt	Champaign-Urbana	13,087	0.3	7% / 8%	73%	−31 / −3
Pike	Small towns and rural Illinois	11,116	0.3	8% / 8%	68%	−64 / −10
Pope	Small towns and rural Illinois	3,200	0.3	11% / 10%	67%	−60 / −10
Pulaski	Small towns and rural Illinois	3,983	0.2	12% / 10%	60%	−34 / +10
Putnam	Small towns and rural Illinois	4,498	0.1	7% / 8%	74%	−23 / −7
Randolph	Small towns and rural Illinois	23,995	0.4	8% / 8%	61%	−50 / −7
Richland	Small towns and rural Illinois	12,014	0.5	8% / 8%	65%	−53 / −8
Rock Island	Davenport-Moline-Rock Island	110,666	0.3	7% / 7%	61%	+10 / +1
St. Clair	St. Louis	195,281	0.2	11% / 11%	63%	+8 / +14
Saline	Small towns and rural Illinois	18,414	0.2	8% / 8%	58%	−49 / −6
Sangamon	Springfield	152,307	0.5	7% / 7%	66%	−5 / +4
Schuyler	Small towns and rural Illinois	5,634	0.3	11% / 9%	67%	−47 / −8
Scott	Small towns and rural Illinois	3,907	0.2	7% / 8%	67%	−61 / −11
Shelby	Small towns and rural Illinois	16,308	0.5	10% / 9%	72%	−60 / −10
Stark	Peoria	4,161	0.5	9% / 8%	67%	−46 / −8
Stephenson	Small towns and rural Illinois	34,472	0.2	7% / 8%	62%	−19 / −3
Tazewell	Peoria	101,706	0.3	7% / 7%	67%	−27 / −4
Union	Small towns and rural Illinois	13,380	0.1	8% / 8%	62%	−43 / −7
Vermilion	Small towns and rural Illinois	55,432	0.3	6% / 7%	54%	−36 / −2
Wabash	Small towns and rural Illinois	8,788	0.2	8% / 8%	62%	−54 / −7
Warren	Small towns and rural Illinois	12,754	0.4	7% / 6%	62%	−25 / −5
Washington	Small towns and rural Illinois	10,791	0.2	9% / 9%	70%	−57 / −6
Wayne	Small towns and rural Illinois	12,381	0.2	7% / 8%	68%	−71 / −9
White	Small towns and rural Illinois	10,662	0.5	9% / 8%	67%	−59 / −8
Whiteside	Small towns and rural Illinois	42,882	0.4	8% / 7%	63%	−15 / −5
Will	Chicago-Naperville-Elgin	535,898	0.4	5% / 5%	66%	+2 / +10
Williamson	Small towns and rural Illinois	52,649	0.2	9% / 8%	64%	−39 / −2
Winnebago	Rockford	216,761	0.2	6% / 6%	59%	+1 / +3
Woodford	Peoria	29,151	0.2	6% / 7%	73%	−42 / −2

Sources

Records: ACS PUMS 2020–2024 5-year, Illinois, adults 18+
Tables: ACS 2020–2024 5-year tables B01001, B01001B/D/H/I, B15001, B19001, B23025, B25008, B26001; out of sample: B21001
Geography: 2020 Census tract to 2020 PUMA relationship file; tract population B01003; metro areas, OMB delineation of July 2023
Citizenship: ACS 2020–2024 5-year table B05003 (raked)
Party lean: Modelled. Priors: Cooperative Election Study 2024 common content (Harvard Dataverse doi:10.7910/DVN/X11EP6, CC0), citizen respondents in the Census Midwest, validated 2024 vote and 7-point party ID with leaners as partisans. Calibration: 2024 county presidential returns, MIT Election Data and Science Lab (Harvard Dataverse doi:10.7910/DVN/VOQCHQ, CC0), presidential votes standing in for ballots cast.