Panama Canal Zone
The Panama Canal Zone () was an unincorporated territory of the United States from 1903 to 1979, centered on the Panama Canal and surrounded by the Republic of Panama. The zone consisted of the canal and an area generally extending on each side of the centerline, excluding Panama City and Colón, which otherwise would have been partly within the limits of the Zone. Its border spanned three of Panama's provinces. When reservoirs were created to assure a steady supply of water for the locks, those lakes were included within the Zone.
Panama Canal expansion project
By January 2016, Panama's President Varela indicated that he anticipated the expansion to be complete around May 2016. The expanded canal began commercial operation on 26 June 2016. The first ship to cross the canal using the third set of locks was a modern New Panamax vessel, the Chinese-owned container ship "Cosco Shipping Panama." The United States dispatched a navy ship to Panama to demonstrate U.S. naval power to the Chinese ship.