Telegraph – revolution in communication of the 19th century The invention of the telegraph in the first half of the 19th century (commercialized by Samuel Morse in 1844) was a technological breakthrough comparable to the later emergence of the Internet. This device, using electrical impulses to transmit coded messages (in Morse code), radically shortened communication time – from weeks to seconds. The key significance of the telegraph was evident in journalism (rapid transmission of news), diplomacy, and railroad management. It also became a tool of war – during the American Civil War (1861-1865) both sides used it intensively. Although in the 20th century the telegraph was replaced by the telephone and radio, its legacy endures: Morse code is still used in rescue operations, and its operating principle initiated the era of telecommunications. The telegraph proved that technology could overcome the barrier of time and space, changing the face of civilization.