Samuel Morse developed the first successful electric telegraph system using a code of dots and dashes.
Morse worked with Alfred Vail to create a practical telegraph system in the 1830s and early 1840s. Their apparatus sent electrical pulses through a wire, while a receiving device marked those pulses on paper. The associated code represented letters and numbers with combinations of short and long signals.
On May 24, 1844, Morse sent the famous first long-distance message from Washington, DC, to Baltimore: “What hath God wrought.” Congress had funded the experimental telegraph line, which demonstrated that messages could travel far faster than physical mail.
Morse did not discover electricity or invent every component of the telegraph. Joseph Henry’s electrical work influenced the field, and Alfred Vail made major technical and coding contributions. The original Morse code also differed from the standardized International Morse Code later used around the world.