Almost 87 percent of the total U.S. population lived in 1,253 mostly urban counties, counties where at least half the population lived in urban areas.

Median income in those counties was $59,970 for the most recent five-year period. The poverty rate was 14.3 percent.

For individual counties, median income ranged from $20,795 to $129,588 and poverty rates ranged from 2.9 percent to 48.2 percent. Loudoun County, Va., had the highest median household income among urban counties during the 2013-2017 period while East Carroll Parish, La., and Brooks County, Texas, had among the highest poverty rates for urban counties.

Across all counties, those that were mostly urban were often among those with the highest median household income (Loudoun County, Va.; Fairfax County, Va.; Howard County, Md.; Falls Church City, Va.; and Arlington County, Va.).

Of the mostly urban counties, Falls Church City, Va.; Lincoln County, S.D.; Douglas County, Colo.; and Loudoun County, Va., had among the lowest poverty rates.