Edwards County was formed in 1814, named after the first governor of the territory of Illinois, Ninian Edwards. The original boundaries of the county ran from where the Bompas enters the Wabash (near Grayville), west to the third meridian (near Mt. Vernon), and north to Canada, including portions of Wisconsin and Michigan. The country seat was Palmyra, near what is now Mt. Carmel and Patton in Wabash County, Illinois.