USS Modoc, an 1175-ton Casco-class light draft monitor built at Greenpoint, New York, was completed as a spar-torpedo vessel in June 1865. She had no active service, spending her entire Navy career laid up "in ordinary" at Philadelphia, Pennsylvania. Modoc was renamed Achilles in June 1869, but received her original name back less than two months later. She was sold for scrapping in August 1875.