The telegraph was the earliest reliable method of instant long-distance communication that used electricity to transmit information. Its inventor was Samuel Morse, who is known as the father of the telegraph.
The telegraph invented by Samuel Morse was patented in the United States in 1837. In 1844, Morse traveled from Washington to Baltimore to send the first telegraph in human history. In the packed Capitol, Morse used his hands, which were trembling with excitement, to operate the telegraph machine he had spent more than ten years developing.
Telegraph information is sent in the form of electrical signals through dedicated switching lines. The signals use codes to replace letters and numbers. The commonly used code is Morse code. With the popularization of telephones, faxes, etc., telegraphs are rarely used.