The telegraph was invented by Charles Wheatstone and William Cooke. The trans-Atlantic telegraph cable is completed. It transmits messages at a rate of seven words per minute. In short, the telephone. The first commercial telephone exchange opens in New Haven, Connecticut, serving 21 subscribers.
Numbers replace names at switching offices.
The first commercially successful long-distance line opens, stretching 45 miles between Boston and Providence, Rhode Island. Almon B. Strowger patents the first machine-switching system for a central office. The First Central Office Exchange begins using common battery for talking and signaling using electricity for all phones. Previously, customers provided their own batteries. Guglielmo Marconi completes the first wireless transmission over 2 kilometers.