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.

SS Vaterland was an ocean liner launched on 3 April 1913 and began service in 1914 for Germany's Hamburg America Line. The ship, second of three running mates and then the largest passenger ship in the world, made her first voyage to New York arriving on 21 May 1914 under the command of a Commodore and four Captains of the German Naval Reserve to celebrations featuring German and American officials at the line's Hoboken facilities.