Randolph County is a county located in the U.S. state of Illinois. As of 2000, the population was 33,893. Its county seat is Chester.
Owing to its role in the state's history, the county motto is "Where Illinois Began."
The Kaskaskia River flows into the Mississippi River in Randolph County. At this point the Mississippi, which usually defines the border between Illinois and Missouri, is entirely in Illinois. The Mississippi changed its course in the late-nineteenth century, leaving Kaskaskia, the former state capitol, on the west side of the River. The boundary of the State, however, follows the old course of the River, leaving Illinois with an enclave on the western shore of the Mississippi River.
The Mississippi River has played a prominent role in the county's history, altering its boundaries in 1881 when it severed the isthmus that connected Kaskaskia to the Illinois mainland, destroying the original village of Kaskaskia and forcing its historic cemetery to be relocated across the river to Fort Kaskaskia. Crains Island
, southeast of Chester, is another enclave of Illinois west of the Mississippi that was created by a change in the river's course.
There were 12,084 households out of which 31.30% had children under the age of 18 living with them, 56.00% were married couples living together, 9.20% had a female householder with no husband present, and 30.80% were non-families. 26.90% of all households were made up of individuals and 13.80% had someone living alone who was 65 years of age or older. The average household size was 2.46 and the average family size was 2.99.
In the county the population was spread out with 22.10% under the age of 18, 9.60% from 18 to 24, 30.40% from 25 to 44, 22.30% from 45 to 64, and 15.60% who were 65 years of age or older. The median age was 38 years. For every 100 females there were 116.40 males. For every 100 females age 18 and over, there were 119.90 males.
The median income for a household in the county was $37,013, and the median income for a family was $44,766. Males had a median income of $30,837 versus $21,501 for females. The per capita income for the county was $17,696. About 7.10% of families and 10.00% of the population were below the poverty line, including 14.10% of those under age 18 and 8.50% of those age 65 or over.
| Year | Republican | Democratic | Other |
|---|---|---|---|
| 2004 | 54.00% 8,076 | 45.27% 6,771 | 0.73% 109 |
| 2000 | 49.88% 7,127 | 47.55% 6,794 | 2.56% 366 |
| 1996 | 37.0% 5,422 | 50.7% 7,419 | 12.3% 1,806 |
| 1992 | 29.6% 4,899 | 51.5% 8,529 | 19.0% 3,137 |
| 1988 | 48.3% 7,396 | 51.2% 7,844 | 0.5% 78 |
| 1984 | 59.5% 9,415 | 40.1% 6,355 | 0.4% 59 |
| 1980 | 56.9% 8,810 | 39.1% 6,052 | 4.1% 632 |
| 1976 | 48.1% 8,190 | 51.0% 8,693 | 0.9% 155 |
| 1972 | 60.2% 9,761 | 39.7% 6,440 | 0.1% 14 |
| 1968 | 50.4% 7,681 | 39.0% 5,953 | 10.6% 1,616 |
| 1964 | 38.7% 5,803 | 61.3% 9,199 | 0.0% 0 |
| 1960 | 52.0% 7,988 | 47.9% 7,344 | 0.1% 15 |
| 1956 | 60.0% 8,439 | 40.0% 6,778 | 0.0% 4 |
| 1952 | 54.6% 8,427 | 45.3% 6,998 | 0.1% 13 |
| Dave Leip's Atlas of U.S. Presidential Elections; Randolph County Clerk and Recorder. | |||
Weekly newspapers in the county are The County Journal, which is based in Percy and also covers Perry and Jackson Counties, the Randolph County Herald-Tribune in Chester, the North County News in Red Bud, and the Sparta News-Plaindealer.