As of the 2010 United States Census, there were 295,223 people, 115,033 households, and 79,832 families living in the county. The population density was . There were 126,709 housing units at an average density of . The racial makeup of the county was 95.5% white, 1.7% Asian, 0.7% black or African American, 0.2% American Indian, 0.6% from other races, and 1.4% from two or more races. Those of Hispanic or Latino origin made up 2.1% of the population. In terms of ancestry, 26.9% were Irish, 19.0% were English, 14.8% were Italian, 9.7% were German, 7.3% were French Canadian, 5.6% were Polish, and 3.8% were American.