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 Canal Zone
The treaty led the U.S. government to contract for steamship service to Panama from ports on both coasts. When the California Gold Rush began in 1848, traffic through Panama greatly increased, and New Granada agreed to allow the Panama Railroad to be constructed by American interests. This first "transcontinental railroad" opened in 1850. There were riots in Panama City in 1856; several Americans were killed. US warships landed Marines, who occupied the railroad station and kept the railroad service from being interrupted by the unrest. The United States demanded compensation from New Granada, including a zone wide, to be governed by US officials and in which the United States might build any "railway or passageway" it desired. The demand was dropped in the face of resistance by New Granadan officials, who accused the United States of seeking a colony.