As of the census of 2000, there were 38,890 people, 14,952 households, and 10,870 families living in the county. The population density was 91 people per square mile. There were 15,890 housing units at an average density of 37 per square mile. The racial makeup of the county was 95.73% White, 2.30% Black or African American, 0.31% Native American, 0.25% Asian, 0.02% Pacific Islander, 0.31% from other races, and 1.08% from two or more races. 0.69% of the population were Hispanic or Latino of any race. There were 14,952 households out of which 34.00% had children under the age of 18 living with them, 59.70% were married couplesliving together, 9.20% had a female householder with no husband present, and 27.30% were non-families. 23.50% of all households were made up of individuals and 9.40% had someone living alone who was 65 years of age or older. The average household size was 2.56 and the average family size was 3.01. In the county, the population was spread out with 26.20% under the age of 18, 7.90% from 18 to 24, 28.70% from 25 to 44, 24.60% from 45 to 64, and 12.60% who were 65 years of age or older. The median age was 37 years. For every 100 females there were 95.90 males. For every 100 females age 18 and over, there were 92.90 males. The median income for a household in the county was $43,139, and the median income for a family was $50,430. Males had a median income of $38,265 versus $26,241 for females. The per capita income for the county was $19,542. About 5.10% of families and 7.60% of the population were below the poverty line, including 9.90% of those under age 18 and 7.60% of those age 65 or over.
2010 census
As of the 2010 United States Census, there were 40,097 people, 15,329 households, and 10,925 families living in the county. The population density was. There were 16,755 housing units at an average density of. The racial makeup of the county was 94.7% white, 2.2% black or African American, 0.4% Asian, 0.4% American Indian, 0.4% from other races, and 1.9% from two or more races. Those of Hispanic or Latino origin made up 1.1% of the population. In terms of ancestry, 27.6% were German, 14.9% were Irish, 14.3% were American, and 11.8% were English. Of the 15,329 households, 33.7% had children under the age of 18 living with them, 55.9% were married couples living together, 10.2% had a female householder with no husband present, 28.7% were non-families, and 23.9% of all households were made up of individuals. The average household size was 2.56 and the average family size was 3.02. The median age was 39.7 years. The median income for a household in the county was $49,246 and the median income for a family was $58,433. Males had a median income of $44,920 versus $32,847 for females. The per capita income for the county was $23,438. About 10.0% of families and 12.9% of the population were below the poverty line, including 18.4% of those under age 18 and 6.3% of those age 65 or over.
Politics
Champaign County is a Republican stronghold county in presidential elections, it has only voted Democratic 3 times since 1912.
