Sun Shipbuilding in Chester, Pennsylvania launched on January 11, 1940 the freighter Mormacmail. The ship was christened by the daughter of George Holt, the vice-president of the Moore-McCormack Line. The U.S. Navy acquired the ship and converted into the first escort carrier and commissioned her USS Long Island AVG-1. The escort carriers or "Baby Flattops" were relatively easy to turn out compared to a fleet carrier and were vital to the U.S. war effort. They were used for training new pilots, ferrying aircraft, troop and supply transportation, convoy escort duty and for hunting submarines.

Long Island was used for most of the described duties during her war career. After the war she was sold for scrap, but later repurchased by commercial interests and remained in use until the late 1960's or early 70's.