Adams County is the westernmost county in the U.S. state of Illinois. As of the 2020 census, the population was 65,737. Its county seat is Quincy. Adams County is part of the Quincy, IL–MO Micropolitan Statistical Area.

Hancock County is a county in the U.S. state of Illinois. According to the 2020 census, it has a population of 17,620. Its county seat is Carthage, and its largest city is Hamilton. The county is composed of rural towns with many farmers.