The telephone was invented in 1876 by Alexander Graham Bell. Scottish born Bell was a teacher for the deaf at Boston University. In researching ways to teach the deaf, he experimented with transmitting sound via electricity. Teaching by day, he spent many hours of his spare time, developing a form of telephone. He applied for a form of patent on March 7, 1876. Within five years, private telephone exchanges were in place in most US cities. It was an invention that caught on very quickly.