Constructing the Liberty Ships

When the SS Patrick Henry was launched on September 27, 1941, the Japanese attack on Pearl Harbor was more than two months away. The "Liberty Ship" program was evidence that the United States had begun to mobilize for battle well before it declared war on Japan. Liberty Ships were not pleasant to look at, but they became the naval workhorses of the war. The cargo ships were built in 17 port cities around the country, and the national average to build one ship was 42 days at a cost of $1.8 million each. To attract publicity for the program, the SS Robert E. Peary was constructed in four days and 15 hours. Using pre-fabrication and newly created mass-production methods, Liberty Ships were produced for the United States and its allies faster than the German submarines could sink them. More than 2,700 ships were built during the four-year program.