"The county received its name from the Hon. John Edgar, one of the first three Judges of the Illinois County, when that municipality was a part of the "Old Dominion".He was a resident of old Kaskaskia when Gen. St. Clair arrived there, in February, 1790, under instructions of Gen. Washington.His wife was one of the most accomplished women of that day, and was a devoted American.Her husband had been an officer in the British army in the War of Independence; but, owing to the intense loyalty of his wife, was induced, mainly by her, to join the patriot cause.Edgar was a large portly man."This quote is from pg.237 "The History of Edgar County, Illinois" pub. 1879. (There is no information as to the editor/author of the book).Hope this is of help to you all.