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.
Latin America–United States relations
Roosevelt was able to reverse a previous decision by the Walker Commission in favour of a Nicaragua Canal and pushed through the acquisition of the French Panama Canal effort. Panama was then part of Colombia, so Roosevelt opened negotiations with the Colombians to obtain the necessary permission. In early 1903, the Hay–Herrán Treaty was signed by both nations, but the Colombian Senate failed to ratify the treaty.