A: Manhattan, New York, New York, United States, B: San Francisco, California, United States, C: Carson City, Nevada, United States, D: Omaha, Nebraska, United States, E: Salt Lake City, Utah, United States, F: Sacramento, California, United States
On October 24, 1861 the first transcontinental telegraph line constructed by the Western Union Telegraph Company between St. Joseph, Missouri, and Sacramento connected the existing telegraph network in the eastern United States to a small network in California, by means of a link between Omaha, Nebraska and Carson City, Nevada, via Salt Lake City. Even though messages sent over the network had to be relayed between various cities, the near instantaneous speed of communication was a dramatic development.
On October 25, 1861 Stephen J. Field, the Chief Justice of California, sent the first cross-country message on the new line to President Abraham Lincoln in Washington, DC.In his message Field told Lincoln he thought the ability to commicate quickly would would help the Western states stay loyal to the Union during the Civil War. Field wrote:
"In the temporary absence of the Governor of the State I am requested to send you the first message which will be transmitted over the wires of the telegraph Line which Connect the Pacific with the Atlantic States the People of California desire to Congratulate you upon the Completion of the great work.
"They believe that it will be the means of stengthening the attachment which bind both the East & West to the Union & they desire in this the first message across the continent to express their loyalty to that Union & their determination to stand by the Government in this its day of trial They regard that Government with affection & will adhere to it under all fortunes
Twenty years earlier, in 1841, it took 110 days for the news of the death of President William Henry Harrison to reach Los Angeles, travelling by sea, around Cape Horn in a clipper ship.
As a result of the completion of this line, the Pony Express was immediately obsolete, and it ceased operations two days later.
The single transcontinental telegraph line was operated until 1869, when it was replaced by a multi-line telegraph constructed alongside the route of the Transcontinental Railroad.