The Type C7 ship (Lancer Class) is a United States Maritime Administration (MARAD) designation for a cargo ship and the first US purpose-built container ship. The vessels were constructed in US shipyards and entered service starting in 1968. As US-built ships they were Jones Act qualified for shipments between US domestic ports. Under the Jones Act, domestic US maritime trade is restricted to US-built and flagged vessels of US owners and crewed by predominantly US-citizens. The last active Lancer container-configured ship was scrapped in 2019. Lancers of the vehicle Roll-on/Roll-off (RO/RO) configuration remain held in the Ready Reserve Force, National Defense Reserve Fleet and the US Navy Military Sealift Command. All are steam powered.