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.
Panama
The US intent to influence the area, especially the Panama Canal's construction and control, led to the separation of Panama from Colombia in 1903 and its establishment as a nation. When the Senate of Colombia rejected the Hay–Herrán Treaty on January 22, 1903, the United States decided to support and encourage the Panamanian separatist movement