Clay County, Illinois

Clay County is a county located in the U.S. state of Illinois. As of the 2010 census, the population was 13,815. Its county seat is Louisville. In 1950, the U.S. Census Bureau placed the mean center of U.S. population in Clay County.

Clay County, Illinois

Clay County is a county located in the U.S. state of Illinois. As of the 2010 census, the population was 13,815. Its county seat is Louisville. In 1950, the U.S. Census Bureau placed the mean center of U.S. population in Clay County.