Today marks 150 years since Alexander Graham Bell made the first telephone call from his Boston lab to his assistant in a nearby room.

Today marks 150 years since Alexander Graham Bell made the first telephone call from his Boston lab to his assistant in a nearby room.

The breakthrough came just days after Bell received a patent for telephone technology, four days after his 29th birthday. His successful prototype used acidified water to convert acoustic oscillations created by the human voice into electrical, voice-mimicking oscillations that could travel to a receiver (watch how). The design closely resembled that of American electrical engineer Elisha Gray, who unsuccessfully contested Bell’s patent in court. Bell went on to commercialize his telephone by founding the Bell Telephone Co., which eventually became the American Telephone and Telegraph Co., or AT&T.

Nearly 100 years after Bell’s first phone call, Motorola engineer Marty Cooper made the first cellphone call. Listen to his story on our “1440 Explores” podcast here.