# Warren County, Illinois

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.
* Warren County from the time of its creation to 1831
* Between 1831 and 1835, Mercer County was temporarily attached to Warren until it could organize its own county government.
* Warren County between 1835 and 1841
* Warren County in 1841, reduced to its current borders by the creation of Henderson County

## Geography

According to the U.S. Census Bureau, the county has a total area of 543 square miles (1,410 km$^2$), of which 542 square miles (1,400 km$^2$) is land and 0.6 square miles (1.6 km$^2$) (0.1%) is water.

### Climate and weather

In recent years, average temperatures in the county seat of Monmouth have ranged from a low of 15 °F (−9 °C) in January to a high of 85 °F (29 °C) in July, although a record low of −27 °F (−33 °C) was recorded in February 1905 and a record high of 110 °F (43 °C) was recorded in July 1936. Average monthly precipitation ranged from 1.62 inches (41 mm) in January to 4.33 inches (110 mm) in July.

### Adjacent counties

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

## Demographics

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 32.6 inhabitants per square mile (12.6/km$^2$). There were 7,682 housing units at an average density of 14.2 per square mile (5.5/km$^2$). 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.
United States presidential election results for Warren County, Illinois :
| Year | Republican | Republican | Democratic | Democratic | Third party(ies) | Third party(ies) |
| Year | No. | % | No. | % | No. | % |
| 2024 | 4,579 | 61.30% | 2,711 | 36.29% | 180 | 2.41% |
| 2020 | 4,676 | 59.01% | 3,090 | 39.00% | 158 | 1.99% |
| 2016 | 4,275 | 54.76% | 2,987 | 38.26% | 545 | 6.98% |
| 2012 | 3,618 | 46.28% | 4,044 | 51.73% | 156 | 2.00% |
| 2008 | 3,637 | 45.12% | 4,286 | 53.17% | 138 | 1.71% |
| 2004 | 4,474 | 52.90% | 3,938 | 46.56% | 45 | 0.53% |
| 2000 | 3,899 | 51.09% | 3,524 | 46.18% | 208 | 2.73% |
| 1996 | 2,974 | 41.02% | 3,500 | 48.28% | 776 | 10.70% |
| 1992 | 3,325 | 39.37% | 3,661 | 43.35% | 1,460 | 17.29% |
| 1988 | 4,584 | 55.54% | 3,617 | 43.82% | 53 | 0.64% |
| 1984 | 5,846 | 63.59% | 3,318 | 36.09% | 29 | 0.32% |
| 1980 | 5,667 | 62.47% | 2,756 | 30.38% | 648 | 7.14% |
| 1976 | 5,822 | 59.25% | 3,808 | 38.75% | 196 | 1.99% |
| 1972 | 7,021 | 70.15% | 2,969 | 29.67% | 18 | 0.18% |
| 1968 | 5,877 | 60.00% | 3,085 | 31.50% | 833 | 8.50% |
| 1964 | 5,258 | 52.95% | 4,670 | 47.02% | 3 | 0.03% |
| 1960 | 7,221 | 65.25% | 3,835 | 34.66% | 10 | 0.09% |
| 1956 | 7,580 | 71.63% | 2,996 | 28.31% | 6 | 0.06% |
| 1952 | 8,020 | 72.88% | 2,973 | 27.02% | 11 | 0.10% |
| 1948 | 6,738 | 66.20% | 3,367 | 33.08% | 74 | 0.73% |
| 1944 | 7,085 | 64.12% | 3,926 | 35.53% | 39 | 0.35% |
| 1940 | 7,790 | 61.17% | 4,878 | 38.30% | 67 | 0.53% |
| 1936 | 6,919 | 55.51% | 5,409 | 43.39% | 137 | 1.10% |
| 1932 | 5,498 | 48.84% | 5,610 | 49.83% | 150 | 1.33% |
| 1928 | 7,915 | 73.61% | 2,681 | 24.93% | 157 | 1.46% |
| 1924 | 6,912 | 65.07% | 2,440 | 22.97% | 1,271 | 11.96% |
| 1920 | 6,309 | 69.41% | 2,236 | 24.60% | 545 | 6.00% |
| 1916 | 6,294 | 56.44% | 4,498 | 40.33% | 360 | 3.23% |
| 1912 | 2,627 | 44.03% | 2,080 | 34.86% | 1,259 | 21.10% |
| 1908 | 3,283 | 54.12% | 2,327 | 38.36% | 456 | 7.52% |
| 1904 | 3,563 | 61.35% | 1,559 | 26.84% | 686 | 11.81% |
| 1900 | 3,618 | 56.97% | 2,501 | 39.38% | 232 | 3.65% |
| 1896 | 3,394 | 55.24% | 2,604 | 42.38% | 146 | 2.38% |
| 1892 | 2,725 | 50.69% | 2,294 | 42.67% | 357 | 6.64% |

## Transportation
### Transit

* Burlington Trailways
* List of intercity bus stops in Illinois

### Airport

* Monmouth Municipal Airport "info". Retrieved August 2, 2008.

### 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

### Unincorporated communities

* Berwick
* Cameron
* 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