Jersey County is a county located in the U.S. state of Illinois. The population was 22,622 in the 2008 official US Census estimate. The county seat is Jerseyville.
History
It is the former home of the Kickapoo, Menomini, Potawatomi, and Illiniwek Confederation American Indians. The first European explorers to visit the area, Father Marquette and Louis Jolliet, arrived in 1673, where they encountered the fearsome painting of the Piasa bird. The present day Pere Marquette State Park, located near Grafton, is named in Father Marquette's honor, and a monument to him is located at the park.
