In the United States, what is the longest river east of the Mississippi River?

The longest river east of the Mississippi River in the United States is the Ohio River at 981 miles long. It flows southwesterly from western Pennsylvania to its mouth on the Mississippi River at the southern tip of Illinois. The river flows through or along the border of six states, and its drainage basin includes parts of 14 states. In addition to its commercial value, it is the source of drinking water for three million people.

Because the Ohio River flows westward, it was a valuable source of westward movement in the early pioneer days of America. Settlers would travel to its mouth, then up the Mississippi River, and from there continue westward up the connecting Missouri River or at some point along any of the way over land routes. Today, the river is heavily industrialized and populated and sees traffic from large barge cargoes carrying oil, steel and other industrial goods. There are several major cities located along its northern and southern banks including Cincinnati, Ohio; Pittsburgh, Pennsylvania; and Louisville, Kentucky.

The Tennessee River, which happens to be a tributary of the Ohio River, is the second longest river east of the Mississippi River at 935 miles in length.