The American Merchant Marine refers to the fleet of U.S. civilian-owned merchant ships that transport goods and materials during peacetime and wartime. This fleet plays a crucial role in supporting the economy by facilitating international trade and providing shipping services. The merchant marine is also vital for national defense, as it can be called upon to transport military personnel and supplies during conflicts. The Merchant Marine Act of 1920, also known as the Jones Act, established regulations for maritime commerce in the United States. This act requires that goods transported between U.S. ports be carried on ships that are built, owned, and operated by American citizens. This legislation aims to promote a strong domestic shipping industry and ensure the availability of vessels for national security needs.