Dispersion in Delaware

The 2010 census data, just released, shows a strong trend toward dispersal in Delaware. The state’s largest county, New Castle, added eight percent to its population, rising from 500,000 to 538,000. All of that gain in the county was outside the city of Wilmington, which lost three percent of its population (from 73,000 to 71,000). Wilmington and New Castle County is a former metropolitan area that has been engulfed by the growth of the larger Philadelphia metropolitan area. Philadelphia has spread from its Pennsylvania base, with a large share of the metropolitan area now in New Jersey, along with New Castle County in Delaware and Cecil County in Maryland.

Delaware’s other two counties, both to the south of New Castle County, are growing rapidly as the population moves outside metropolitan areas. Kent County, with the state capital in Dover, gained 28 percent from 127,000 to 162,000. Southern most Sussex County added 26 percent to its population, rising from 157,000 to 197,000. Thus, much smaller Sussex County added more people than New Castle County, which began the decade of the 2000s with three times the population.