In general the term electrical telegraph refers to a signalling system where an operator makes and breaks an electrical contact with a telegraph key which results in an audible signal at the other end produced by a telegraph sounder which is interpreted and transcribed by a human. Morse and Vail's first telegraphs used a pen and paper system to record the marks of the Morse Code, and interpreted the marks visually however, operators soon realized that they could "read" the clicking of the receiver directly by ear. Systems which automatically read the signals and print formed characters are generally called teletype rather than telegraph systems. Some electrical telegraphs used indicators which were read visually rather than by ear. The most notable of these was the early transatlantic telegraph cable.
Within 30 years of its invention, the telegraph network crossed the oceans to every continent, making instant global communication possible for the first time. Its development allowed newspapers to cover significant world events in near real-time, revolutionised business, particularly trading businesses, and allowed huge fortunes to be won and lost in an orgy of investment in research and infrastructure building reminiscent of the 1990s dot-com boom. Few inventions have ever had greater impact.
On January 6, 1838 Morse first publicly demonstrated the electrical telegraph. The first electronic telegram was sent by Morse on May 24, 1844 from Baltimore to Washington, D.C, and said "What hath God wrought!" (from the Biblical book of Numbers 23:23: Surely there is no enchantment against Jacob, neither is there any divination against Israel: according to this time it shall be said of Jacob and of Israel, What hath God wrought!).
See also: telegraphy, telegraph key.