As of the 2000 United States Census, there were 18,780 people, 6,940 households, and 5,149 families in the county. The population density was 48 people per square mile (19/km2). There were 7,408 housing units at an average density of 19 per square mile (7/km2). The racial makeup of the county was 98.12% White, 0.34% Black or African American, 0.20% Native American, 0.29% Asian, 0.11% Pacific Islander, 0.30% from other races, and 0.63% from two or more races. 1.08% of the population were Hispanic or Latino of any race. 37.1% were of German, 11.9% Danish, 9.0% Irish, 7.8% American and 7.0% English ancestry.