Panama Canal Railway
The Panama Railway also operated a significant shipping line, connecting its service with New York and San Francisco. It ran a Central American line of steamships linking Nicaragua, Costa Rica, San Salvador, and Guatemala to Panama City. The shipping service was greatly expanded when canal construction began. Ships included the SS "Salvador", SS "Guatemala", SS "Cristobel", and , which became the first of the ships to cross the completed canal in 1914.
In 1904 the United States took over the license to build and operate the canal. The choice to use locks and an artificial lake (Gatun) meant that the old railway route from 1855 had to be changed because it followed the Chagres River valley, which would be flooded by the lake. Also, the railway would be extended and altered continuously for the building process. The stock of the Panama Railway Company, vital in canal construction, was entirely controlled by the United States Secretary of War.
Panama–United States relations
The evolution of the relation between Panama and the USA has followed the pattern of a Panamanian project for the recovering of the territory of the Canal of Panama, a project which became public after the events of May 21, 1958, November 3, 1959, and then on January 9, 1964. The latter day is known in Panama as the Martyrs' Day (Panama), in which a riot over the right to raise the Panamanian flag in an American school became the vicinity of the Panama Canal.