USS Benton, a 1033-ton ironclad river gunboat, was converted from a catamaran snagboat at Saint Louis, Missouri, for the Army's Western Gunboat Flotilla. Commissioned in February 1862, she took an active part in the Federal operations to open the Mississippi River and its tributaries. In the Spring of 1862, she was present at the captures of Island Number Ten, Fort Pillow and Memphis. During the Summer, Benton was in action with the Confederate ironclad Arkansas near Vicksburg, Mississippi, and participated in an expedition up the Yazoo River. She was transferred to the Navy in October 1862, and continued her service as the Mississippi Squadron's flagship into 1863.

In December 1862, Benton was damaged by Confederate gunfire during another operation on the Yazoo River. She was one of the ships that ran past Vicksburg on 16 April 1863 and bombarded Grand Gulf, Mississippi, later in that month. She participated in an attack on Fort DeRussy, Arkansas, in May, then provided gunfire support for the siege of Vicksburg. In March-May 1864, Benton was involved in the Red River expedition, in Louisiana, and returned to that vicinity in June 1865 during operations that followed the formal end of the Civil War. USS Benton was decommissioned in July 1865 and sold the following November.