United States territorial acquisitions
The Panama Canal Zone was an unorganized US territory located within the Republic of Panama. It was established under the Hay–Bunau-Varilla Treaty in 1903 and disestablished in 1979 under the Torrijos–Carter Treaties. Panama gained full control over the Panama Canal in 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.