USS Cimarron, an 860-ton side-wheel "double-ender" gunboat, was built at Bordentown, New Jersey. Commissioned in July 1862, she operated on the James River, Virginia, during July-September 1862, supporting the Army in the area and several times engaging Confederate forces.

Cimarron next joined the South Atlantic Blockading Squadron, her assignment for the rest of the Civil War. She was active along the coasts and rivers of South Carolina, Georgia and Florida, participating in the blockade of the Confederacy and engaging enemy positions ashore. She took part in attacks on fortifications at St. John's River, Florida, in September 1862, Charleston, South Carolina, in August 1863, and in the Stono River, S.C., in February 1864. As a blockader, she captured three prizes, including the steamer Jupiter on 13 September 1863. Cimarron decommissioned at Philadelphia, Pennsylvania, in August 1865 and was sold the following November.