At the outbreak of World War II in 1939, President Franklin D. Roosevelt called upon America to rearm. Increasing the number of submarines became a goal. Because existing shipbuilders could not meet production schedules, the U.S. Navy approached Charles C. West, president of the Manitowoc Shipbuilding Company, and requested that his firm build submarines.
Government contracts led to the expansion and modernization of the Manitowoc Shipbuilding Company facilities. Workers and engineers rapidly developed innovative contruction methods, including side-launching of submarines. Ultimately, the Manitowoc Shipbuilding Company employed some 7,000 workers in three shifts, seven days a week.
U.S.S. Peto, launched in 1942, became the first of twenty-eight fleet submarines built at Manitowoc. The submarines were towed to New Orleans via the Illinois-Mississippi Waterway using a special floating dry dock. U.S.S. Rasher, a Manitowoc submarine, sank 99,901 tons of Japanese shipping, the second highest total for an American submarine. Four Manitowoc submarines, Golet, Kete, Lagato, and Robalo, along with 336 officers and enlisted men were lost during the war.