Panama Canal
Colombia, France, and later the United States controlled the territory surrounding the canal during construction. The US continued to control the canal and surrounding Panama Canal Zone until the 1977 Torrijos–Carter Treaties provided for handover to Panama. After a period of joint American–Panamanian control, in 1999, the canal was taken over by the Panamanian government. It is now managed and operated by the government-owned Panama Canal Authority.
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.