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 Panama Canal
French engineer and financier Philippe-Jean Bunau-Varilla played a key role in changing U.S. attitudes. Bunau-Varilla had a large stake in the failed French canal company, and stood to make money on his investment only if the Panama Canal was completed. Extensive lobbying of U.S. lawmakers coupled with his support of a nascent independence movement among the Panamanian people led to a simultaneous revolution in Panama and the negotiation of the Hay–Bunau-Varilla Treaty which secured both independence for Panama and the right for the U.S. to lead a renewed effort to construct the canal. Colombia's response to the Panamanian independence movement was tempered by U.S. military presence; the move is often cited as a classic example of the era of gunboat diplomacy.