At the 2000 United States Census, there were 470,212 people, 169,711 households and 124,907 families residing in the county. The population density was 1,003 per square mile (387/km2). There were 174,379 housing units at an average density of 372 per square mile (144/km2). The racial makeup of the county was 87.20% White, 2.80% Black or African American, 0.12% Native American, 6.26% Asian, 0.04% Pacific Islander, 2.01% from other races, and 1.56% from two or more races. 7.79% of the population were Hispanic or Latino of any race. Among those responding for first ancestry, 22.8% were of Italian, 19.9% Irish, 16.3% German, 8.6% English and 7.5% Polish ancestry according to Census 2000.