Well back in 1876 an ol' boy named Bell
Invented a contraption that we know so well
By the 1950's they're in everybodys home
It's a crazy little thing they call a telephone
Now there's one in every corner, in the back of every bar
You can get one in your briefcase, on a plane, or in your car
-Why Haven’t I Heard from You (Reba McEntire)
It was on March 10, 1876 that Alexander Graham Bell called his assistant in the next room by speaking into his new invention. From Bell’s journal:
I then shouted into M [the mouthpiece] the following sentence: "Mr. Watson, come here -- I want to see you." To my delight he came and declared that he had heard and understood what I said.
I asked him to repeat the words. He answered, "You said 'Mr. Watson -- come here -- I want to see you.'" We then changed places and I listened at S [the speaker] while Mr. Watson read a few passages from a book into the mouthpiece M. It was certainly the case that articulate sounds proceeded from S. The effect was loud but indistinct and muffled.
The new “telephone” wasn’t free of controversy. There has long been talk of Bell stealing the idea and the technology from Elisha Gray. Bell won the patent, and is therefore known as the inventor of the telephone. Link