As of the 2010 United States Census, there were 421,407 people, 163,445 households, and 102,768 families living in the county. The population density was . There were 184,841 housing units at an average density of . The racial makeup of the county was 76.9% white, 5.2% Asian, 2.3% black or African American, 1.7% American Indian, 0.6% Pacific islander, 9.5% from other races, and 3.8% from two or more races. Those of Hispanic or Latino origin made up 22.2% of the population. In terms of ancestry, 16.9% were German, 13.1% were Irish, 11.8% were English, 7.2% were Italian, and 4.7% were American.