This study presents a comprehensive historical analysis of merchant shipping on the high seas and associated shipbuilding under sovereign U.S. jurisdiction from precolonial times to the present. The volume traces the history of the merchant marine and shipbuilding industries; identifies U.S. policy developments that have affected those industries; and assesses the impact of these policies (or lack thereof) on the abilities of the U.S. shipbuilding industry and merchant fleets to meet U.S. economic and defense requirements, particularly in times of national emergency and conflict, It breaks new ground in its analysis of the contributions of the major segments of these industries to the general development of the United States, its military strength, and its expanding role in world affairs.