1838: Alfred Vail demonstrates a telegraph system using dots and dashes

(Wikipedia) Alfred Lewis Vail (September 25, 1807, in Morristown, New Jersey – January 18, 1859) was a machinist and inventor. Vail was central, with Samuel F.B. Morse, in developing and commercializing the telegraph between 1837 and 1844. Vail and Morse were the first two telegraph operators on Morse's first experimental line between Washington, DC, and Baltimore, and Vail took charge of building and managing several early telegraph lines between 1845 and 1848. He was also responsible for several technical innovations of Morse's system, particularly the sending key and improved recording registers and relay magnets. Continued

Images: Smithsonian Institution, Wikipedia