US Merchant Marine

The United States Merchant Marine played a vital role in the conduct of World War II by providing maritime transport for troops, equipment, fuel, and supplies needed by American and Allied forces in all theaters of operation. Although not part of the regular armed forces, the U.S. Merchant Marine was placed under government control when the United States entered the war and operated in close coordination with the U.S. Navy.

Before the conflict, the US Merchant Marine had a limited and aging fleet. Beginning in 1941, the government launched a massive shipbuilding program under the authority of the War Shipping Administration, created in 1942. Thousands of ships were built, including Liberty Ships and Victory Ships, to replace losses and support the global logistical effort. These ships were operated by civilian crews from the Merchant Marine, who were quickly recruited and trained to meet the growing demand.

From the moment the US entered the war, American merchant sailors were exposed to combat, particularly during the Battle of the Atlantic. Convoys carrying goods to the United Kingdom, the Soviet Union, and North Africa were targeted by German submarines, causing significant losses in ships and human lives, especially between 1942 and 1943. Merchant ships were gradually armed with defensive guns, which were operated by detachments from the US Navy called Naval Armed Guards, while navigation remained the responsibility of civilian crews.

The Merchant Marine participated in all major amphibious operations during the conflict. It transported forces during the landings in North Africa in 1942, Sicily and Italy in 1943, Normandy in June 1944, and then during operations in southern France. In the Pacific, it played a central role in the logistics of the island campaigns, transporting troops and supplies over long distances and providing continuous support to the forces engaged against Japan.

Merchant seamen also served on Arctic routes to the Soviet Union, in the Indian Ocean, in the Mediterranean, and in active combat zones until the end of the war. Their missions continued after the fighting ended, notably for the repatriation of troops, prisoners of war, and military equipment.

Between 1941 and 1945, approximately 250,000 men served in the US Merchant Marine. More than 9,000 of them died during the war, mainly as a result of torpedo attacks, bombing, or naval mines. By the end of the war, the US merchant fleet had become the largest in the world. After 1945, the Merchant Marine was gradually reduced and returned to civilian duties, while many ships built during the war were placed in reserve or transferred to commercial operators. The experience gained during World War II confirmed the central role of maritime transport in conducting military operations on a global scale.