94.60% were non-Hispanic White, 0.70% were Black, 1.40% were Hispanic, 0.29% were Native American, 0.27% were Asian, 0.01% were Native Hawaiian or Pacific Islander and 2.74% were some other race or more than one race.

[11] As of the census[12] of 2000, there were 18,404 people, 6,834 households, and 5,029 families residing in the county.

The population density was 32 people per square mile (12 people/km2).

The racial makeup of the county was 99.28% White, 0.07% Black or African American, 0.10% Native American, 0.14% Asian, 0.01% Pacific Islander, 0.10% from other races, and 0.30% from two or more races.

There were 6,834 households, out of which 36.70% had children under the age of 18 living with them, 64.10% were married couples living together, 6.20% had a female householder with no husband present, and 26.40% were non-families.

23.00% of all households were made up of individuals, and 11.20% had someone living alone who was 65 years of age or older.