As of the 2010 United States Census, there were 42,376 people, 16,501 households, and 11,629 families residing in the county. The population density was . There were 18,202 housing units at an average density of . The racial makeup of the county was 94.5% white, 0.8% Asian, 0.7% black or African American, 0.2% American Indian, 0.1% Pacific islander, 2.4% from other races, and 1.3% from two or more races. Those of Hispanic or Latino origin made up 5.7% of the population. In terms of ancestry, 28.8% were German, 13.1% were American, 12.8% were Irish, and 9.2% were English.