USS Keystone State was a wooden sidewheel steamer that served in the Union Navy during the American Civil War. She was a fast ship for her day and was used effectively to blockade Confederate ports on the Atlantic coast. She participated in the capture or destruction of 17 blockade runners. In addition to her military service, Keystone State had a lengthy commercial career before the war. Renamed San Francisco, she also sailed commercially after the war. The ship was built in 1853 and scrapped in 1874. Construction and characteristics Keystone State was commissioned by the Philadelphia and Savannah Steam Navigation Company. She was intended to carry passengers and cargo as one of a pair of vessels offering weekly service between the two cities. Her hull was built at Philadelphia, Pennsylvania at the Vaughn & Lynn Shipyard. Her frame was built of live oak and locust wood, and she was planked with white oak. The ship was long, with a beam of , and a depth of hold of . She displaced 1,364 tons. She was propelled by a coal-fired side-lever steam engine. Steam was produced in two boilers. The engine had a single cylinder that was in diameter, with a stroke of . The engine was built by the Southwark Foundry & Machine Company of Philadelphia, operated by Merrick & Sons. The steam engine drove paddlewheels which were in diameter with face of . Her maximum speed was 14 knots, but the state of her hull and machinery reduced her maximum speed to as little as 10.5 knots on occasion. The ship had two masts and was rigged as a bark. She could sail, but was slower and less maneuverable than under steam. As originally built, she had 46 staterooms, a couple of salons, a dining room, ladies' parlor, smoking room, and a passenger library. She had running water in the washrooms, storage for ice, and cold rooms to keep food fresh for passengers. Her original cost was reported as $180,000. Keystone State was launched on 18 June 1853. Sea trials of the newly completed ship took place on 19 September 1853. She was immediately placed in commercial service. Her namesake, The Keystone State, is a nickname for Pennsylvania. Philadelphia and Savannah Steam Navigation Company (18531861) Keystone State completed her first trip from Philadelphia to Savannah on 23 September 1853 after a 56.5 hour run. This was considered a fast