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 manned by predominantly US-citizen crews. 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.

United States Lines was the trade name of an organization of the United States Shipping Board (USSB), Emergency Fleet Corporation (EFC) created to operate German liners seized by the United States in 1917. The ships were owned by the USSB and all finances of the line were controlled by the EFC. Among the notable ships of this period was Leviathan, a contender for largest ship in the world for a time.