The Alabama Drydock and Shipbuilding Company (ADDSCO) located in Mobile, Alabama, was one of the largest marine production facilities in the United States of America during the 20th century. It began operation in 1917, and expanded dramatically during World War II; with 30,000 workers, including numerous African Americans and women, it became the largest employer in the southern part of the state. During the defense buildup, which included other shipyards, Mobile became the second-largest city in the state, after Birmingham.