The electrical telegraph was developed in the 1830s and 1840s by a number of inventors, most notably by Samuel Morse. The inventor's Morse Code revolutionized communication, allowing for the simple transmission of messages across lines by assigning a sequence of dashes and dots to each letter of the alphabet.
Morse sent his first telegraph from Washington, D.C., to Baltimore in 1844. Twenty-two years later, a telegraph line had been laid across the Atlantic Ocean. While the telegraph slowly fell out of widespread use and was completely obsolete around the start of the 21st century, it is credited for being the gateway innovation that led to the telephone, fax machine and Internet.