The yard became involved in World War II production in the early shipbuilding expansions initiated by the Two-Ocean Navy Act of July 1940.
Western Pipe & Steel sold the shipyard to Bethlehem Shipbuilding Corporation in 1925.
In 1997 Southwest Marine operated four shipyards, which they sold to the Carlyle Group.
The shipyard was located at 1047 South Seaside Ave, San Pedro.
[1] Bethlehem Shipbuilding San Pedro destroyers built from 1942 to 1945: [2] Southwestern was the second largest of three steel shipyards in the Ports of Los Angeles and Long Beach active during the World War I shipbuilding boom, responsible for 28% of the tonnage built there for the United States Shipping Board.