Warren County is a county in the U.S. state of Illinois. According to the 2020 census, it had a population of 16,835. Its county seat is Monmouth.

History Warren County was organized in 1825 out of Pike County which consisted of all portions of the state north and west of the Illinois River before 1825. Henderson County was formed in 1841 from the western area of Warren County.

Warren County was named for Dr. Joseph Warren, killed at the Battle of Bunker Hill in 1775. He is believed to have been the first officer to die in the Revolutionary War.

The current courthouse, constructed of red Portage stone, was completed in 1895.

Geography According to the U.S. Census Bureau, the county has a total area of , of which is land and (0.1%) is water.

Climate and weather

In recent years, average temperatures in the county seat of Monmouth have ranged from a low of in January to a high of in July, although a record low of was recorded in February 1905 and a record high of was recorded in July 1936. Average monthly precipitation ranged from in January to in July.

Adjacent counties Mercer County (north) Knox County (east) Fulton County (southeast) McDonough County (south) Henderson County (west)

Demographics

2020 census

As of the 2020 census, the county had a population of 16,835. The median age was 40.9 years, with 21.3% of residents under the age of 18 and 21.0% aged 65 years or older. For every 100 females there were 98.1 males, and for every 100 females age 18 and over there were 96.5 males age 18 and over.

The racial makeup of the county was 82.2% White, 3.5% Black or African American, 0.4% American Indian and Alaska Native, 2.0% Asian, 0.1% Native Hawaiian and Pacific Islander, 5.6% from other races, and 6.2% from two or more races. Hispanic or Latino residents of any race comprised 10.6% of the population.

54.6% of residents lived in urban areas, while 45.4% lived in rural areas.

There were 6,720 households in the county, of which 27.4% had children under the age of 18 living in them. Of all households, 48.3% were married-couple households, 19.3% were households with a male householder and no spouse or partner present, and 25.2% were households with a female householder and no spouse or partner present. About 31.1% of all households were made up of individuals and 15.3% had someone living alone who was 65 years of age or older.

There were 7,602 housing units, of which 11.6% were vacant. Among occupied housing units, 74.4% were owner-occupied and 25.6% were renter-occupied. The homeowner vacancy rate was 2.5% and the rental vacancy rate was 8.3%.

Racial and ethnic composition +Warren County, Illinois – Racial and ethnic compositionRace / Ethnicity (NH = Non-Hispanic)Pop 1980Pop 1990Pop 2000Pop 2010 Pop 2020% 1980% 1990% 2000% 2010% 2020White alone (NH)21,21318,51817,67215,58213,49496.67%96.54%94.33%88.00%80.15%Black or African American alone (NH)3603552962875771.64%1.85%1.58%1.62%3.43%Native American or Alaska Native alone (NH)31203032310.14%0.10%0.16%0.18%0.18%Asian alone (NH)636961933290.29%0.36%0.33%0.53%1.95%Native Hawaiian or Pacific Islander alone (NH)x included in the Asian category in the 1980 Censusx included in the Asian category in the 1990 Census17915xx0.09%0.05%0.09%Other race alone (NH)411269460.19%0.06%0.03%0.05%0.27%Mixed race or Multiracial (NH)x not an option in the 1980 Censusx not an option in the 1990 Census146205554xx0.78%1.16%3.29%Hispanic or Latino (any race)2352075071,4901,7891.07%1.08%2.71%8.41%10.63%Total21,94319,18118,73517,70716,835 100.00%100.00%100.00%100.00%100.00%

2010 census At the 2010 United States census, there were 17,707 people, 6,918 households and 4,617 families residing in the county. The population density was . There were 7,682 housing units at an average density of . The racial makeup of the county was 91.3% white, 1.7% black or African American, 0.5% Asian, 0.2% American Indian, 0.1% Pacific islander, 4.5% from other races, and 1.6% from two or more races. Those of Hispanic or Latino origin made up 8.4% of the population. In terms of ancestry, 25.2% were German, 14.7% were Irish, 11.3% were English, 10.0% were Swedish, and 5.5% were American.

Of the 6,918 households, 29.6% had children under the age of 18 living with them, 52.2% were married couples living together, 9.7% had a female householder with no husband present, 33.3% were non-families, and 28.2% of all households were made up of individuals. The average household size was 2.40 and the average family size was 2.91. The median age was 39.6 years.

The median household income was $41,636 and the median family income was $49,623. Males had a median income of $40,289 and females $25,460. The per capita incomewas $20,047. About 11.0% of families and 13.4% of the population were below the poverty line, including 18.1% of those under age 18 and 10.6% of those age 65 or over.

Politics Warren County is located in Illinois's 17th Congressional District and is currently represented by Democrat Cheri Bustos. For the Illinois House of Representatives, the county is split between the 93rd district, currently represented by Republican Norine Hammond, and the 94th district, currently represented by Randy Frese. The county is located in the 47th district of the Illinois Senate, and is currently represented by Republican Jil Tracy.

In presidential elections, Warren County voted for the Republican Party's candidate in every election from 1936 through 1988, often by a wide margin. From 1992 to 2012, the contest in Warren County was more competitive, with the Democratic Party's candidate winning four out of six times. In every election since then, the county has voted Republican by increasing double-digit margins.

Transportation

Transit Burlington Trailways List of intercity bus stops in Illinois

Airport Monmouth Municipal Airport

Major highways U.S. Highway 34 U.S. Highway 67 Illinois Route 94 Illinois Route 116 Illinois Route 135 Illinois Route 164

Law enforcement

State Illinois State Police District 14, Macomb

County Warren County Sheriff's Office In a scene in the 2018 film "Halloween", the local sheriff drives a car that says Warren County Sheriff's Department. Confirming that the fictional town of Haddonfield is located in Warren County.

Municipal Alexis Police Department, Alexis Monmouth Police Department, Monmouth

Volunteer Warren County/Monmouth Auxiliary Police Corps

Communities

City Monmouth

Villages Alexis (partly in Mercer County) Kirkwood Little York Roseville

Census-designated place

Cameron

Unincorporated communities

Berwick Coldbrook Eleanor Gerlaw Greenbush Larchland Ormonde Ponemah Shanghai City Smithshire Swan Creek Utah Youngstown

Townships Warren County is divided into these townships:

Berwick Cold Brook Ellison Floyd Greenbush Hale Kelly Lenox Monmouth Point Pleasant Roseville Spring Grove Sumner Swan Tompkins

Education School districts include: - Text list

Abingdon-Avon Community Unit School District 276 Bushnell-Prairie City Community Unit School District 170 Galesburg Community Unit School District 205 Monmouth-Roseville Community Unit School District 238 United Community School District 304 West Central Community Unit School District 235

See also National Register of Historic Places listings in Warren County, Illinois

References

External links Warren County Circuit Court Welcome to Warren Co., IL AHGP