South Jersey County Map

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 Jerseyville, with a population of 8,337 in 2010. The county's smallest incorporated community is Otterville, with a population of 87.
  • Country: United States
  • State: Illinois
  • Founded: February 28, 1839
  • Named for: New Jersey
  • Seat: Jerseyville
  • Largest city: Jerseyville
  • Congressional district: 15th
Data from: en.wikipedia.org