The telegraph, invented by Samuel Morse in 1838, relies on electrical signals sent by a sender. The sender creates the signals by tapping a coded alphabet (Morse code) on a telegraph machine.

Photograph by John Scofield, National Geographic
  • On January 6, 1838, Samuel Morse demonstrated his new communications device, known as a telegraph, for the first time. The telegraph converted a simple code alphabet (known as Morse code) tapped out on a single key into electrical signals. These signals were then sent along a cable and decoded on the receiving end. Anywhere a cable could be laid—across mountains or under oceans—telegraphic messages could be sent.

    Within 30 years of its first installation near Morristown, New Jersey, the global telegraph network reached every continent except Antarctica. This made instant worldwide communication possible for the first time in history. Before the telegraph, information could only be transported over long distances by foot or on a vehicle. The telegraph made delivery of information nearly instantaneous, transforming industries from finance to journalism.

  • Term Part of Speech Definition Encyclopedic Entry
    cable Noun

    strong set of cords or wire ropes.

    electrical signal Noun

    information or message sent by an electric charge or series of charges.

    instantaneously Adverb

    happening very quickly, in an instant.

    network Noun

    series of links along which movement or communication can take place.

    telecommunications Noun

    the science and technology of sending and receiving information over long distances using electric, radio, or light signals.

    telegraph Noun

    system of communication involving devices connected through electrical wires.

    transport Verb

    to move material from one place to another.