History of the Panama Canal
During World War II, the canal proved a vital part of the U.S. military strategy, allowing ships to transfer easily between the Atlantic and Pacific. Politically, the Canal remained a territory of the United States until 1977, when the Torrijos–Carter Treaties began the process of transferring territorial control of the Panama Canal Zone to Panama, a process completed on 31 December 1999.
History of the United States (1865–1918)
Although U.S. capital investments within the Philippines and Puerto Rico were small, some politicians hoped they would be strategic outposts for expanding trade with Latin America and Asia, particularly China. That never happened and after 1903 American attention turned to the Panama Canal as the key to opening new trade routes. The Spanish–American War thus began the active, globally oriented American foreign policy that continues to the present day.