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Definition: telegraph

A low-speed communications device that transmits up to approximately 150 bps. Telegraph grade lines, stemming from the days of Morse code, cannot transmit a voice conversation. In 1843, the U.S. Congress authorized USD $30,000 to build a telegraph line between Baltimore and Washington, DC. The wire was strung onto 700 poles which were placed approximately 300 feet apart. On May 24, 1844, at the U.S. Supreme Court in Washington, Samuel Morse tapped out "What hath God wrought" via telegraph to his assistant Alfred Vail who was waiting at a Baltimore railroad station, some 40 miles away.

The Days of the Morse Code
Data was transmitted at about four to six bits per second in the latter half of the 1800s, which was as fast as a human hand could tap out Morse code. The unit on the right is the telegraph key. A metal bar on the receiver (left) simply banged against another bar when the current passed through, creating a clicking sound.

Synonymous With Telegraphy
In the mid-1800s, Western Union consolidated long distance communications in the U.S. The first transcontinental line began in 1871. By the turn of the century, there were more than a million miles of telegraph lines.