Marshall County is a county located in the U.S. state of Illinois. According to the 2010 census, it had a population of 12,640. Its county seat is Lacon.Marshall County is part of the Peoria, IL Metropolitan Statistical Area.
Marshall County is a county located in the U.S. state of Illinois. According to the 2010 census, it had a population of 12,640. Its county seat is Lacon.Marshall County is part of the Peoria, IL Metropolitan Statistical Area.