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Setting the Stage

In 1936, Congress passed the Merchant Marine Act, creating the U.S. Maritime Commission to oversee "... that the United States shall have a merchant marine…to provide shipping service essential for maintaining the flow of such domestic and foreign waterborne commerce at all times, capable of serving as a naval and military auxiliary in time of war or national emergency, owned and operated under the United States flag…, composed of the best-equipped, safest, and most suitable types of vessels…, and supplemented by efficient facilities for shipbuilding and ship repair."¹ The fleet of ships responsible for this mission is called the U.S. Merchant Marine.

At the time the act was passed, the majority of the ships in the merchant fleet were over 20 years old. The original plan was to build 50 ships per year for 10 years. However, World War II began in 1939, when Hitler's Germany invaded Poland. The United States realized that the existing construction program was not adequate to meet the changing world situation. During World War II the Merchant Marine was nationalized, that is, the U.S. government controlled the cargo and the destinations, contracted with private companies to operate the ships, and put guns and Navy personnel (Armed Guard) on board. The government trained civilian men to operate the ships and assist in manning the guns through the U.S. Maritime Service.

With Hitler's attack on Great Britain in 1940, the need for the United States to increase ship production became critical. The British could no longer produce ships in great numbers and also needed food and supplies. The United States knew that if Great Britain fell it would have no allies in Western Europe. Under the Lend-Lease program (which enabled the president to transfer arms and equipment to any nation deemed vital to the defense of the United States), the U.S. agreed to build commercial ships for Great Britain. American ship builders began to construct these ships using an old, but reliable, English design.

In 1939 the German Navy launched submarine warfare in the North Atlantic Ocean to enforce a naval blockade against Great Britain. Their submarines, called Unterseebooten or U-Boats, sank great numbers of merchant ships approaching the British Isles. Under these pressures, the United States greatly increased the production of its own merchant fleet. Cargo ships were needed to ferry supplies to allies if the United States entered the war. The United States decided to modify the English design being used for the Lend-Lease ships. The new emergency cargo ships came to be known as the Liberty ships. Yet, between 1939 and 1940, only 82 vessels were constructed. In 1941, Congress passed the Ship Warrants Act, giving the Maritime Commission power to allot ship construction priorities. Since existing shipyards were working full capacity on naval contracts, the Maritime Commission established 18 new shipyards to work on these identical merchant ships. They were built on a common design in assembly-line fashion along the West, East, and Gulf coasts of the United States. Parts were manufactured in every state in the country.

Following the Japanese attack on Pearl Harbor on December 7, 1941 and U.S. entry into World War II, ships were being sunk by German U-Boats almost as fast as they were being built. The Maritime Commission called for 2,000 ships to be constructed by the end of 1943. (The Japanese also inflicted a toll on supply ships in the Solomon Islands and New Guinea, but following their naval and air losses at Coral Sea and Midway, in mid-1942, they were less of a problem to merchant shipping than the Germans.) The ship building effort was a success. Finally, the United States had enough ships to keep pace with the losses caused by the U-Boats.

However, the Liberty ships were slow and small. Their design had a weakness in the hull that caused ships to sometimes break in two. In 1943, the United States started a new emergency cargo ship program to replace the Liberty ships. The newer ships were bigger and faster with better engines. These ships were designated Victory ships. While the Liberty ships were designed to be the workhorse of the war, Victory ships could continue to be used after the war as part of the regular merchant fleet.

The Liberty and Victory ships were adapted to suit the operational needs of each branch of the military service. Many carried cargo, while others were fitted out as troop carriers. Some were used as tankers carrying fuel for ships, vehicles and aircraft. Still others were fitted out as hospital ships or used to transport enemy prisoners of war. Ultimately, both the Liberty ships and Victory ships served with distinction in both the Atlantic and Pacific Oceans during World War II.

¹ Merchant Marine Act, 1936, U.S. Code website [], (Washington, D.C.: Government Printing Office).



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