Analysis of information sources in references of the Wikipedia article "Territorial evolution of the United States" in English language version.
A survey was made and a map drawn up showing the boundary lines of the Punta Paitilla military reservation. Various areas were determined with reference to high and low water and the old and new city boundary lines. Permanent monuments were set and a description written up by metes and bounds. A tracing was made of the map of the military reservation known as area 'A'.
... it was not until the year 1918, when the Governor of the Canal Zone addressed a communication to the Secretary of Foreign Affairs of the Republic of Panama stating that the United States Government would require 50.6 hectares, that the exact area expropriated was definitely known.
Approvals: United States – May 26, 1977 [;] Mexico – May 26, 1977
A survey was made and a map drawn up showing the boundary lines of the Punta Paitilla military reservation. Various areas were determined with reference to high and low water and the old and new city boundary lines. Permanent monuments were set and a description written up by metes and bounds. A tracing was made of the map of the military reservation known as area 'A'.
Approvals: United States – May 26, 1977 [;] Mexico – May 26, 1977