USA HISTORY

Detailed explanation-1: -There are four primary types of telegraph machines: optical telegraphs, electrical telegraphs, Morse telegraphs, and wireless telegraphs. Eventually, transcontinental telegraph lines were established for worldwide communication, too.

Detailed explanation-2: -A prolific inventor, Granville Woods developed the railroad telegraph, a device that transmitted messages, through static electricity, between moving trains. Born in Columbus, Ohio, Woods was formally educated until the age of ten when he took a job in a machine shop.

Detailed explanation-3: -Beginning in 1850, submarine telegraph cables allowed for the first rapid communication between continents. Electrical telegraph networks permitted people and commerce to transmit messages across both continents and oceans almost instantly, with widespread social and economic impacts.

Detailed explanation-4: -By 1895, the Italian Guglielmo Marconi had demonstrated wireless telegraphy over a distance of 2.4 kilometers. Instead of using a metal wire, he used electromagnetic waves. Marconi then moved to London, where he continued to develop his telegraph technology.