telegraphs

A telegraph is a system for transmitting messages over long distances by electrical or optical signals. Historically the term covers a range of technologies and the networked infrastructure that carried coded messages, commonly called telegrams. Telegraphy transformed communication in the 19th century by enabling near-instant transmission of information between cities, countries and continents.

Early non-electric systems included optical semaphore lines, notably Claude Chappe’s visual telegraph in France (late 18th century). The electric telegraph, developed in the 1830s and 1840s, used coded electrical pulses over wires. Important figures include William Fothergill Cooke and Charles Wheatstone, who installed Britain’s early commercial lines, and Samuel F. B. Morse, whose 1844 Baltimore–Washington line and Morse code became widely influential. Submarine telegraphy linked continents after mid-19th-century ventures culminating in a durable transatlantic cable in 1866.

Telegraph networks supported rail operations, finance, journalism and diplomacy, and fostered international news agencies and commercial exchange. Messages were encoded (most notably in Morse code) and relayed by trained operators. Over time telegraphy developed standards, routing practices and undersea cable technologies.

The invention of the telephone, radio and later digital communications progressively displaced telegraph services through the 20th century. Elements of telegraphy, such as encoded signaling and global network concepts, persist in modern telecommunications.