As of the census[9] of 2000, there were 19,210 people, 7,669 households, and 5,391 families residing in the county. The population density was 20 people per square mile (8/km²). There were 9,657 housing units at an average density of 10 per square mile (4/km²). The racial makeup of the county was 86.86% White, 6.79% Black or African American, 0.19%Native American, 0.16% Asian, 0.02% Pacific Islander, 4.84% from other races, and 1.14% from two or more races. 11.36% of the population were Hispanic or Latino of any race. 27.0% were of Czech, 24.1% German, 9.1% American and 5.1% Irish ancestry according to Census 2000. 86.3% spoke English, 7.7% Spanish, 4.6% Czech and 1.2% German as their first language.

There were 7,669 households out of which 30.00% had children under the age of 18 living with them, 57.70% were married couples living together, 9.30% had a female householder with no husband present, and 29.70% were non-families. 27.60% of all households were made up of individuals and 16.60% had someone living alone who was 65 years of age or older. The average household size was 2.44 and the average family size was 2.98.

In the county, the population was spread out with 24.20% under the age of 18, 6.90% from 18 to 24, 23.50% from 25 to 44, 23.60% from 45 to 64, and 21.80% who were 65 years of age or older. The median age was 42 years. For every 100 females there were 93.10 males. For every 100 females age 18 and over, there were 88.50 males.

The median income for a household in the county was $29,132, and the median income for a family was $36,760. Males had a median income of $26,988 versus $17,537 for females. The per capita income for the county was $16,398. About 10.20% of families and 13.20% of the population were below the poverty line, including 15.20% of those under age 18 and 18.40% of those age 65 or over.