Morse’s first telegraph message: words travel along a wire

On May 24, 1844, Samuel Morse operated a telegraph in the US Capitol and sent a message to Alfred Vail in Baltimore. A line spanning tens of kilometres connected Washington with the Mount Clare railway depot.

The public demonstration put the wire and its operators into practical service. The message travelled electrically, and the participants could compare the letters sent and received.

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An operator used a key to switch the current, encoding letters in combinations of short and long signals. At the receiving end, the apparatus recorded signals for a trained operator to interpret. A messenger no longer had to carry the words between the two cities.

The equipment and code developed with Vail joined power, wire, recording and human interpretation. Reliable communication required shared signal conventions at both ends and a maintained line between them.

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The message was “What hath God wrought?” The Library of Congress preserves an outgoing paper tape from the demonstration. Its visible signal marks have a different appearance from the ordinary written letters of a message.

The tape and Morse’s archival papers identify the date, sending location and recipient. Words travelled through a circuit to another city and also survived as a physical record.

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Telegraph lines subsequently connected more cities. Railway stations, newspapers and commercial users required rapid messages; wires along transport corridors allowed train movements and business information to be coordinated electrically. Operators became part of the network’s daily work.

The demonstration contained several elements of later telecommunications: a shared code, a fixed connection, terminals at both ends and a record of reception.

References: [1]