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 Panama (1821–1903)
Naval operations during the Spanish–American War (1898–1901) served to convince U.S. President Theodore Roosevelt that the United States needed to control a canal somewhere in the Western Hemisphere. This interest culminated in the Spooner Bill of June 29, 1902, providing for a canal through the isthmus of Panama, and the Hay–Herrán Treaty of January 22, 1903, under which Colombia gave consent to such a project in the form of a 100-year lease on an area 10 kilometers wide. This treaty, however, was not ratified in Bogotá, and the United States, determined to construct a canal across the isthmus, intensively encouraged the Panamanian separatist movement.