As of the 2010 United States Census, there were 743,159 people, 285,956 households, and 188,005 families residing in the county. The population density was . There were 306,754 housing units at an average density of . The racial makeup of the county was 81.9% White, 3.8% Black or African American, 3.1% Asian, 0.4% American Indian, 8.2% from other races, and 2.6% from two or more races. Those of Hispanic or Latino origin made up 16.5% of the population. In terms of ancestry, 23.3% were Irish, 17.1% were Italian, 12.6% were English, 6.1% were German, and 3.6% were American.