The Arkansas River is a major tributary of the Mississippi River. It generally flows to the east and southeast as it traverses the U.S. states of Colorado, Kansas, Oklahoma, and Arkansas. The river's source basin lies in Colorado, specifically the Arkansas River Valley. The headwaters derive from the snowpack in the Sawatch and Mosquito mountain ranges. It flows east into Kansas and finally through Oklahoma and Arkansas, where it meets the Mississippi River.

Napoleon was a river port and the county seat of Desha County, Arkansas, from 1838 to 1874. It was located at the confluence of the Arkansas and the Mississippi rivers. Napoleon was badly damaged during the Civil War and then finally abandoned after most of it had washed into the Mississippi River.