Illinois

According to the U.S. Census Bureau, approximately 12.9 million people lived in Illinois in 2013. Cook County, which includes Chicago and many suburbs, is by far Illinois’ largest county, with 5.24 million people, or over 40 percent of the state’s population. It is the second-most populous county in the United States. Including the five bordering “collar counties” of Will, DuPage, Kane, McHenry, and Lake, the Chicago metropolitan area is home to about 65 percent of Illinois’ population.

Among 102 counties in Illinois, 22 have higher poverty rates than Cook County. Though some of Illinois’ highest poverty rates are in rural counties in the southern tip of the state, Cook County—with 923,158 people living below the poverty line in 2012—has about half of the state’s poverty population ...