Chicago, Detroit, Baltimore Lead Nation in Population Loss
The counties that contain Chicago and Detroit and the city of Baltimore were the biggest population losers in the United States from 2015 to 2016, according to a Census Bureau report.
Cook County, Ill., where Chicago is the county seat, had the largest population loss of any county in the country from 2015 and 2016. Between July 1, 2015 and July 1, 2016, Cook County lost a net of 21,324 people to hit 5,203,499, according to the Census Bureau.