Onondaga, a 2592-ton twin-turret monitor, was formerly the U.S. Navy ship of the same name. No longer needed by her original owners after the end of the American Civil War, she was sold to France in March 1867 and had a long career as a unit of that nation's Navy. She was rearmed in French service, receiving 9.4-inch rifled guns in place of her U.S. battery of eight-inch Parrott rifles and XV-inch Dahlgren smoothbores. Onondaga, whose iron hull helped to make her the longest-lived of the larger American-built Civil War era monitors, was scrapped in about 1903-1904.