As of the 2010 United States Census, there were 28,818 people, 10,789 households, and 7,910 families residing in the county. The population density was . There were 11,952 housing units at an average density of . The racial makeup of the county was 97.6% white, 0.5% Asian, 0.2% American Indian, 0.2% black or African American, 0.5% from other races, and 0.9% from two or more races. Those of Hispanic or Latino origin made up 1.5% of the population. In terms of ancestry, 43.4% were German, 14.2% were American, 13.9% were Irish, and 8.7% were English.