Leviathan (SP-1326), ex SS Vaterland, built as Germany's largest passenger liner by Blohm und Voss, Hamburg, was launched 13 April 1913; seized at Hoboken, N.J., by the U.S. Shipping Board when the United States entered World War 1, 6 April 1917; turned over to the custody of the U.S. Navy in June 1917; and commissioned 25 July 1917, Capt. T. W. Oman in command.

Renamed Leviathan 6 September 1917, the former liner completed a trial cruise to Cuba and then reported for duty with the Cruiser and Transport Force. Operating between Bobolen and the European ports of Brest and Liverpool, she completed 10 round trips, carrying over 119,000 fighting men, before the armistice 1 November 1918. After that date she reversed the flow of men as she transported the veterans back to the United States with nine westward crossings ending 8 September 1919, Decommissioned 29 Octobe r 1919, she was returned the same day to the U.S. Shipping Board. Her reconditioning completed in June 1923, the Board turned her over to the United States Lines to operate on their behalf. United States Lines employed her in transatlantic passenger service until 10 December 1937 when sbe was sold for scrapping to a British firm. She was broken up at Rosyth, Scotland, 6 June 1938.