Who invented the telephone?
US Patent Office
Caveat submission on February 14, 1876 for "Transmitting Vocal Sounds Telegraphically," by Elisha Gray, of Chicago, Illinois.
To all whom it may concern: Be it known that I, Elisha Gray, of Chicago, in the county of Cook, and State of Illinois, have invented a new art of transmitting vocal sounds telegraphically, of which the following is a specification:
It is the object of my invention to transmit the tones of the human voice through a telegraphic circuit, and reproduce them at the receiving end of the line, so that actual conversations can be carried on by persons at long distances apart. ... ...
... The obvious practical application of my improvement will be to enable persons at a distance to converse with each other through a telegraphic circuit, just as they now do in each other's presence, or through a speaking tube. I claim, as my invention, the art of transmitting vocal sounds or conversations telegraphically through an electric circuit.