Illinois County, Virginia
Illinois County, Virginia, was a political and geographic region, part of the British Province of Quebec, claimed during the American Revolutionary War on July 4, 1778, by George Rogers Clark of the Virginia Militia as a result of the Illinois Campaign. Though part or all of the area was also claimed by Connecticut and Massachusetts, it was formally organized by the Commonwealth of Virginia later that year.
Source: Wikipedia — Illinois County, Virginia (CC BY-SA 4.0)