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 Panama (1821–1903)
Throughout the period of turmoil, the United States had retained its interest in building a canal through either Nicaragua or Panama. An obstacle to this goal was overcome in December 1901 when the United States and Britain signed the Hay–Pauncefote Treaty. This treaty nullified the provisions of the Clayton–Bulwer Treaty of 1850 and signified British acceptance of a canal constructed solely by or under the auspices of the United States with guarantees of neutrality.