2000 25,267 1990 23,265 1980 23,867 1970 20,995 1960 19,709 1950 18,042 1940 17,037 1930 15,831 1920 17,351 1910 17,602 1900 19,138 1890 15,671 1880 13,795 1870 10,554 1860 8,258 1850 4,761 1840 1,832
As of the census of 2000, there were 25,267 people, 9,727 households, and 7,090 families residing in the county. The population density was 50 people per square mile (19/km²). There were 12,083 housing units at an average density of 24 per square mile (9/km²). The racial makeup of the county was 95.20% White, 0.16% Black or African American, 0.25% Native American, 0.25% Asian, 0.04% Pacific Islander, 3.19% from other races, and 0.92% from two or more races. 5.34% of the population were Hispanic or Latino of any race. 27.7% were of German, 21.1% American, 9.2% English and 8.6% Irish ancestry according to Census 2000.
There were 9,727 households out of which 32.40% had children under the age of 18 living with them, 60.40% were married couples living together, 8.40% had a female householder with no husband present, and 27.10% were non-families. 22.60% of all households were made up of individuals and 11.20% had someone living alone who was 65 years of age or older. The average household size was 2.57 and the average family size was 2.99.
In the county the population was spread out with 25.80% under the age of 18, 7.80% from 18 to 24, 27.80% from 25 to 44, 23.80% from 45 to 64, and 14.80% who were 65 years of age or older. The median age was 38 years. For every 100 females there were 96.80 males. For every 100 females age 18 and over, there were 93.50 males.
The median income for a household in the county was $40,707, and the median income for a family was $46,436. Males had a median income of $33,232 versus $21,431 for females. The per capita income for the county was $18,323. About 4.30% of families and 7.00% of the population were below the poverty line, including 8.80% of those under age 18 and 8.30% of those age 65 or over.