As of the census of 2000, 458,336 people, 181,153 households, and 115,394 families resided in the county.  The population density was 587 people per square mile (227/km²).  There were 196,633 housing units at an average density of 252 per square mile (97/km²).  The Race (United States Census) of the county was 84.78% White, 9.38% African American, 0.86% Native American, 2.09% Asian, 0.03% Pacific Islander, 0.89% from other races, and 1.97% from two or more races. Hispanics or Latinos of any race were 2.44% of the population. About 17.5% were of Italian people, 16.2% Irish people, 12.4% Germans, 9.4% English people, and 6.0% Polish people ancestry according to Census 2000, and 91.4% spoke English language, 2.4% Spanish language and 1.1% Italian language as their first language.. Which ethnic background had the largest population?