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 Southern Command
The Marines protected the Panamanian civilian uprising led by former Panama Canal Company general manager Philippe-Jean Bunau-Varilla guaranteeing his creation of the Panamanian state. Following the signing of the Hay–Bunau-Varilla Treaty granting control of the Panama Canal Zone to the United States, the Marines remained to provide security during the early construction days of the Panama Canal.