Illinois State House District 109

State Legislative District Profile (Lower Chamber)

Overview

District ID
il-hd-109
State
Illinois
Chamber
Lower chamber
District Code
109
Land Area
1,348.4 sq mi
Water Area
7.42 sq mi

Boundary

Boundary of Illinois State House District 109

Boundary as GeoJSON

Source: U.S. Census Bureau TIGER/Line state legislative district boundaries.

Counties

CountyOverlapShare of district landShare of county land
Madison County408.67 sq mi30.3%57.1%
Washington County380.41 sq mi28.2%67.6%
Bond County258.33 sq mi19.2%67.9%
Clinton County247.46 sq mi18.4%52.2%
St. Clair County53.47 sq mi4.0%8.1%

Showing all 5 counties

Places

PlaceOverlapShare of district landShare of place land
Highland city6.75 sq mi0.5%94.3%
Troy city5.62 sq mi0.4%90.1%
Greenville city4.83 sq mi0.4%76.5%
Nashville city3.08 sq mi0.2%99.9%
Breese city2.67 sq mi0.2%99.9%
Okawville village2.02 sq mi0.2%100.0%
Edwardsville city2.00 sq mi0.1%10.0%
O'Fallon city1.88 sq mi0.1%11.9%
Trenton city1.88 sq mi0.1%99.8%
Aviston village1.60 sq mi0.1%100.0%
Hamel village1.19 sq mi0.1%100.0%
Williamson village1.17 sq mi0.1%100.0%
Richview village1.15 sq mi0.1%100.0%
Ashley city1.13 sq mi0.1%100.0%
New Douglas village1.05 sq mi0.1%100.0%
Livingston village1.04 sq mi0.1%100.0%
New Baden village1.04 sq mi0.1%56.8%
Germantown village1.01 sq mi0.1%99.4%
Irvington village1.01 sq mi0.1%100.0%
Addieville village0.99 sq mi0.1%100.0%
St. Libory village0.90 sq mi0.1%93.0%
Maryville village0.89 sq mi0.1%15.4%
Albers village0.85 sq mi0.1%85.3%
St. Jacob village0.83 sq mi0.1%98.2%
Damiansville village0.82 sq mi0.1%100.0%

Showing top 25 of 49 places

Overlapping Congressional Districts

Congressional districtPopulation in bothShare of this district's populationShare of the congressional district's populationShare of this district's land
IL District 1567,32762.0%8.9%49.1%
IL District 1240,47237.3%5.4%50.5%
IL District 137490.7%0.1%0.4%

Source: U.S. Census Bureau 2020 blocks and 2025 block equivalency files (119th Congress, 2024 state legislative plans).

Voters

Registered Voters
82,550
Active Voters
80,870 (98.0%)

Party Registration

This state's voter file does not record party registration.

Turnout by Cycle

CycleGeneralDemocratic PrimaryRepublican Primary
2025–202616,422 (19.9%)0 (0.0%)0 (0.0%)
2023–202461,594 (74.6%)2,608 (3.2%)10,925 (13.2%)
2021–202246,647 (56.5%)2,941 (3.6%)13,035 (15.8%)
2019–202055,519 (67.3%)6,874 (8.3%)9,883 (12.0%)
2017–201841,988 (50.9%)5,380 (6.5%)11,647 (14.1%)
2015–201646,718 (56.6%)7,631 (9.2%)16,431 (19.9%)
2013–201431,003 (37.6%)2,605 (3.2%)6,596 (8.0%)
2011–201237,904 (45.9%)1,675 (2.0%)8,067 (9.8%)

Turnout counts today's registered voters with a counted ballot in the cycle's elections (the odd and even year), as a share of today's registered voters. Voters who have since left the rolls are not counted.

Browse the voter list for this district (premium access; sign-in required)

Source: Civitech voter file snapshot as of 12/15/2025. These are registered voters, separate from the Census population figures. Counts under 10 are suppressed and shown as "<10".

Demographics

Total Population
109,431 (± 1,303)
Median Age
40.8
Median Household Income
$96,443 (± $3,783)
High School Graduate or Higher (age 25+)
94.8%
Bachelor's Degree or Higher (age 25+)
34.7%

Population by Age

GroupPeopleShare
Under 1825,26023.1%
18 to 6464,36458.8%
65 and over19,80718.1%

Population by Race and Hispanic Origin

GroupPeopleShare
Hispanic or Latino (any race)3,0392.8%
White, not Hispanic99,97491.4%
Black, not Hispanic1,8681.7%
Asian, not Hispanic5990.5%
American Indian / Alaska Native, not Hispanic2700.2%
Native Hawaiian / Pacific Islander, not Hispanic200.0%
Some other race, not Hispanic1610.1%
Two or more races, not Hispanic3,5003.2%

Source: U.S. Census Bureau, American Community Survey 2020-2024 ACS 5-year estimates (tables B01001, B01002, B01003, B03002, B15003, B19013) for this state legislative district. Estimates are survey-based; ± figures are 90% margins of error.

Citizen Voting Age Population

Total Citizen Population
108,731
Citizen Voting Age Population (CVAP)
83,545

Citizen Population by Race/Ethnicity

GroupCitizensShare
Non-Hispanic106,14897.6%
Hispanic2,5792.4%
White100,96792.9%
Black1,9071.8%
Asian5120.5%
American Indian / Alaska Native2700.2%
Native Hawaiian / Pacific Islander210.0%
Two or More Races770.1%

Citizen Voting Age Population by Race/Ethnicity

GroupCVAPShare
Non-Hispanic81,90398.0%
Hispanic1,6402.0%
White78,06893.4%
Black2,0622.5%
Asian7150.9%
American Indian / Alaska Native9861.2%
Native Hawaiian / Pacific Islander220.0%
Two or More Races550.1%

Source: Redistricting Data Hub / U.S. Census Bureau CVAP Special Tabulation (2020-2024 ACS 5-year).