Iowan was built by the Maryland Steel Company as one of eight sister ships for the American-Hawaiian Steamship Company. In October 1914, five months after she was delivered to American-Hawaiian, Iowan rammed and sank the United Fruit Company steamer Metapan near the entrance to New York Harbor. After repairs, Iowan resumed inter-coastal service via the Panama Canal. When the canal was temporarily closed by landslides in late 1915, Iowan sailed via the Straits of Magellan until the canal reopened in mid 1916. During World War I, USS Iowan carried cargo, animals, and a limited number of passengers to France, and returned nearly 10,000 American troops after the Armistice.