First successful telephone call (March 10, 1876)
Before the internet, we had the telephone. Well, we still do, but let's be honest, most of us carry our cellphones around because they can get us online anywhere we are. But until the rise of the internet, the telephone was probably the most transformative piece of communication technology the world had ever seen. And on March 10th, 1876, inventor Alexander Graham Bell placed the first successful telephone call to his assistant in the next room over. "Mr. Watson, come here; I want to see you" were the first words Bell spoke and successfully transmitted over his telephone.
Bell, like his father before him, spent much of his career studying speech and voice, becoming a professor of vocal physiology at Boston University in 1873. He eventually spent time working on a system to transmit over a telegraph-like system, building what would become the telephone with engineer Thomas Watson. In June of 1875, Bell and Watson transmitted sound vibrations between two receivers -- no intelligible words were heard, but human-like sounds were heard on the receiving end.
By March of 1876, the system had improved enough that Bell believed it could transmit full speech. He had also filed for a patent for his system, which was awarded just three days before the successful March 10th test. Less than six months later, Bell tested his invention with a call placed over a two-mile distance. Obviously, that's still a long way from the instantaneous, worldwide communication the telephone offers now, but it was a landmark development nonetheless.