A map from 1913 detailing the Panama Canal Zone and completed canal, with an inset map of the entire country of Panama "The dotted lines show the boundary of the territory known as the Canal Zone, a strip ten miles wide, from deep water in the Atlantic to deep water in the Pacific, and extending five miles on each side of the center line of the Canal, which was purchased by the United States from the Republic of Panama. The heavy line shows the Canal, and the crossed line just above it the relocated Panama Railroad. The cities of Colon and Panama, though included in the limits of the Zone, are reserved to the Republic of Panama. The sanitation of these cities is however, under the control of the United States." - Marshall, 1913.