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.
United States involvement in regime change
In 1903, the U.S. aided the secession of Panama from the Republic of Colombia. The secession was engineered by a Panamanian faction backed by the Panama Canal Company, a French–US corporation whose aim was the construction of a waterway across the Isthmus of Panama thus connecting the Atlantic and Pacific Oceans. In 1903, the U.S. signed the Hay-Herrán Treaty with Colombia, granting the United States use of the Isthmus of Panama in exchange for financial compensation. amidst the Thousand Days' War. The Panama Canal was already under construction, and the Panama Canal Zone was carved out and placed under United States sovereignty. The US did not transfer the zone back to Panama until 2000.