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.
Panama–United States relations
The details of the arrangements for U.S. operation and defense of the Canal under the Panama Canal Treaty are spelled out in separate implementing agreements. The Canal Zone and its government ceased to exist when the treaties entered into force and Panama assumed complete jurisdiction over Canal Zone territories and functions, a process which was finalized on December 31, 1999.