The River Defense Fleet was a set of fourteen vessels in Confederate service, intended to assist in the defense of New Orleans in the early days of the American Civil War. All were merchant ships or towboats that were seized by order of the War Department in Richmond and converted into warships by arming each with one or two guns, protecting their engines by an interior bulkhead, and strengthening their bows so they could be used as rams. Although they were nominally a part of the Confederate States Army, all of their officers and most of their crews were civilians. A portion of the fleet was retained in the south part of the Mississippi River and a portion was sent north to defend against Union movement from the north.

USS Mound City was a City-class ironclad gunboat built for service on the Mississippi River and its tributaries in the American Civil War. Originally commissioned as part of the Union Army's Western Gunboat Flotilla, she remained in that service until October 1862. Then the flotilla was transferred to the Navy and she became part of the Mississippi River Squadron, where she remained until the end of the war.