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.
History of Panama (1821–1903)
Furthermore, the United States was entitled to acquire additional areas of land or water necessary for canal operations and held the option of exercising eminent domain in Panama City. Within this territory Washington gained "all the rights, power, and authority . . . which the United States would possess and exercise if it were the sovereign ... to the entire exclusion" of Panama.