USS American Legion, a 13,736-ton transport, was originally built at Camden, New Jersey, as a civilian passenger ship. Completed in July 1921, American Legion was not actively employed until 1926, when she began commercial service between New York and South America. She was laid up in early 1939 due to her owner's financial difficulties but soon was taken over by the War Department for use as the U.S. Army Transport American Legion. Beginning in February 1940, she mainly served along the U.S. east coast and in the Caribbean area, but made one trans-Atlantic round-trip voyage in mid-1940, rescuing the Norwegian Crown Princess and many other persons from the European war zone. Her cargo also included a Swedish 40mm Bofors anti-aircraft gun mounting, which became the prototype for thousands of such guns built for the U.S. Navy during World War II.

In August 1941, after participating in the U.S. build-up in Iceland, the transport was transferred to the Navy and commissioned as USS American Legion (AP-35). She made one voyage to and from the Caribbean, then began a series of repairs to her machinery. In April 1942, the ship began a long trip to the south Pacific, which would be her operating area for nearly two years. In August 1942, she participated in the initial landings on Guadalcanal and for the next six months supported the prolonged and bitter campaign to hold that island. Reclassified as an Attack Transport and given the new hull number APA-17 in February 1943, American Legion's next, and final, combat operation was the Bougainville invasion at the beginning of November 1943.

American Legion returned to the United States for overhaul in December 1943. Once this work was completed in April 1944, she was used as an Amphibious Force training ship in southern California waters for the rest of World War II. After Japan's surrender, she made two trans-Pacific voyages before the end of 1945. USS American Legion was decommissioned in March 1946 and transferred to the War Shipping Administration. She was sold for scrapping in February 1948.