Alfred Vail demonstrates a telegraph system using dots and dashes (this is the forerunner of Morse code).

Samuel Morse sends the message "What hath God wrought" (a Bible quotation, Numbers 23:23) from the Old Supreme Court Chamber in the United States Capitol to his assistant, Alfred Vail, in Baltimore, Maryland to inaugurate the first telegraph line.

Texas is linked by telegraph to the rest of the United States, with the completion of a connection between New Orleans and Marshall, Texas.

First news dispatch by telegraph.

The Atlantic Cable is successfully completed, allowing transatlantic telegraph communication for the first time.

Canada and Bermuda are linked by telegraph cable.

Thomas Edison receives a patent for a two-way telegraph.

The Commercial Pacific Cable Company lays the first Pacific telegraph cable, from Ocean Beach, San Francisco to Honolulu, Hawaii.

Western Union discontinues its Telegram and Commercial Messaging services.