2000 21,751 1990 18,993 1980 21,107 1970 19,889 1960 21,721 1950 23,667 1940 27,014 1930 28,133 1920 31,630 1910 32,439 1900 26,005 1890 21,877 1880 20,336 1870 18,453 1860 15,064 1850 10,141 1840 8,315 1830 4,630 1820 3,498
As of the census of 2000, there were 21,751 people, 7,819 households, and 5,574 families residing in the county. The population density was 49 people per square mile (19/km²). There were 8,804 housing units at an average density of 20 per square mile (8/km²). The racial makeup of the county was 94.11% White, 4.27% Black or African American, 0.31% Native American, 0.13% Asian, 0.02% Pacific Islander, 0.33% from other races, and 0.84% from two or more races. 0.82% of the population were Hispanic or Latino of any race. 25.4% were of American, 18.1% German, 16.8% English and 9.7% Irish ancestry according to Census 2000.
There were 7,819 households out of which 31.90% had children under the age of 18 living with them, 58.10% were married couples living together, 9.30% had a female householder with no husband present, and 28.70% were non-families. 25.30% of all households were made up of individuals and 13.10% had someone living alone who was 65 years of age or older. The average household size was 2.49 and the average family size was 2.96.
In the county the population was spread out with 22.60% under the age of 18, 9.40% from 18 to 24, 30.50% from 25 to 44, 23.50% from 45 to 64, and 14.10% who were 65 years of age or older. The median age was 37 years. For every 100 females there were 115.20 males. For every 100 females age 18 and over, there were 116.30 males.
The median income for a household in the county was $32,976, and the median income for a family was $39,290. Males had a median income of $30,207 versus $20,790 for females. The per capita income for the county was $16,234. About 8.50% of families and 10.90% of the population were below the poverty line, including 13.40% of those under age 18 and 9.00% of those age 65 or over.
Turtle Creek Reservoir
Sullivan County Park & Lake
Sullivan County Farm
Merom Power Station
Sullivan Corn Festival Parade
Sullivan Public Library