sentences:  The population density was 1,322 people per square mile (510/km²).There were 292,780 housing units at an average density of 556 per square mile (215/km²).The racial makeup of the county was 64.02% White, 27.87% Black or African American, 0.35% American Indian/Alaska Native, 3.15% Asian, 0.05% Pacific Islander, 3.01% from other races, and 1.55% from two or more races.