guidon (plural guidons) 1  A small pennant or banner carried by infantry soldiers to direct troop movement. 2  A soldier assigned to carry such a banner.
Within a year or two, Western Union and other telegraph companies were using diplex telegraphs on their busiest lines in major cities. In 1874, Thomas Edison invented the first quadruplex telegraph, which was capable of sending two messages simultaneously in each direction.ears later, quadruplex telegraphs were displaced by two new inventions, multiplex telegraphy capable of eight or more simultaneous transmissions, and the use of teletype machines, which did not require their operators to know Morse Code.
With a $30,000 grant from Congress in 1843, the nation's first telegraph wiring was constructed between Washington DC and Baltimore, Maryland, and on 24 May 24 1844, Morse used a transmitter in the US Supreme Court Chambers to send a message to Vail in Baltimore: What hath God wrought!.