 Kọ itẹsiwaju fun paragirafi yii - Ni Kínní 1779, George Rogers Clark ti Virginia Militia gba Kaskaskia ati Vincennes : láti ọdọ ọgágun Henry Hamilton tó jẹ ọmọ ilẹ Gẹẹsì. Virginia lo anfani aseyori Clark nipa sisọ gbogbo Old Northwest, ti o pe ni Illinois County, Virginia, titi di ọdun 1784, nigbati o fi awọn ẹtọ ilẹ rẹ silẹ si ijọba apapọ. 