As of the 2010 United States Census, there were 40,087 people, 16,210 households, and 10,949 families living in the county. The population density was . There were 19,193 housing units at an average density of . The racial makeup of the county was 96.0% white, 1.5% black or African American, 0.3% Asian, 0.2% American Indian, 0.2% from other races, and 1.8% from two or more races. Those of Hispanic or Latino origin made up 0.9% of the population. In terms of ancestry, 22.3% were German, 15.2% were Irish, 12.4% were English, and 9.6% were American.