Jersey County is a county located in the U.S. state of Illinois. At the 2020 census, it had a population of 21,512. The county seat and largest community is ... Jersey Township · Piasa Township · Mississippi Township · Quarry Township

Located to the north of St. Louis on US 67, Jersey County covers over 240,000 acres and is predominately rural. Jerseyville, the county seat, is the largest ...

Jersey Township is one of eleven townships in Jersey County, Illinois, United States. As of the 2010 census, its population was 10,165 and it contained ...

Jersey County, Illinois is bordered by Macoupin County, Illinois, Calhoun County, Illinois, Greene County, Illinois, St. Charles County, Missouri, and Madison ...