“ In its course it separates the States of Ohio, Indiana, and Illinois from the States of West Virginia and Kentucky. The principal towns on its banks are Pittsburgh, Wheeling, Cincinnati, Louisville (where there are rapids of 22 feet in a mile, with a steamboat canal) , Evansville, New Albany, Madison, Portsmouth, Covington, and Cairo. The river's principal affluents are the Tennessee, Cumberland, Wabash, Kentucky, Great Kanawha, Green, Muskingum and Scioto. ”