The invention of telephone was of a considerable significance in the 20th century and continues to be a prominent invention of all time. In the 1870s, Alexander Graham Bell owned the patent of his device that could transmit speech electrically.
The telegraph was a wire-based electrical system. Graham Bell’s invention of the telephone was the result of improving the design for the telegraph. He began experimenting with electrical signals, by then telegraph was used as a means of communication from around 30 years. The Telegraph had limited use at that time as it was only capable of receiving and sending one message at a time.
Bell had a vast knowledge of how the sound principles worked, and that enabled him to come up with the thought that there may be a possibility of transmitting multiple messages at the same time over the same wire.
He then experimented with the idea of “multiple telegraphs” and came up with “harmonic telegraph,” in which several notes could be sent at the same time on the same wires if the signals had different pitches. This finally resulted in the invention of the telephone.