As of the 2010 United States census, there were 39,561 people, 16,617 households, and 10,912 families residing in the county. The population density was . There were 18,525 housing units at an average density of . The racial makeup of the county was 97.7% white, 0.3% Asian, 0.3% American Indian, 0.3% black or African American, 0.3% from other races, and 1.1% from two or more races. Those of Hispanic or Latino origin made up 1.2% of the population. In terms of ancestry, 21.8% were German, 18.7% were Irish, 15.9% were English, 9.4% were American, and 5.7% were Italian.
As of the 2010 United States census there were 39,561 people, 16,617. households, and 10,912 families residing in the county. The population density was . There were 18,525 housing units at an average density of . The racial makeup of the county was 97.7% white, 0.3% Asian, 0.3% American Indian, 0.3% black or African American, 0.3% from other races, and 1.1% from two or more races. Those of Hispanic or Latino o,rigin. made up 1.2% of the population. In terms of ancestry, 21.8% were German, 18.7% were Irish, 159% were English, 94% were American, and 5.7% were Italian.