Alexander Graham Bell
Bell, chiefly known as a teacher for the hearing-impaired, was working on a harmonic telegraph when he stumbled on telephone principles. He later became one of Edison's chief rivals for control of the telephone and the phonograph on the commercial marketplace.
The son of Edison and Mina, he took over Thomas Edison, Inc., upon his father's retirement. He was the company's director until 1957, when it was sold to McGraw Electric Company.
The chief proponent of the AC power system in the 1880s. He battled Edison for control of the market for decades. By the 1920s it became clear that his system had triumphed, after the invention of a rotary converter by a former Edison employee made flexibility in electric power delivery possible.
Not just the inventor of the Model T car and the owner of an incredible automobile industry, Ford was also a production innovator and a good friend of Edison in the 1910s. Ford once said that Edison was one of the "three greatest inventors of this age."
An English inventor who performed much of the background work on electrical lighting technology before Edison picked up the hunt for an electrical light system in the 1870s and 1880s. When Edison came out with his electrical lighting system, Swan responded with a lawsuit.
Edison's first wife. They were married on Christmas Day, 1871, when Mary was sixteen. They had three children by 1878. Mary was shy and frequently placed under stress by the demands of her husband's absences. She died at the age of twenty-nine, in 1884.
Edison's second wife. They were married on February twenty-four, 1886, when she was nineteen. A woman of strong religious conviction and independent personality, she was a constant companion to Edison during his later years. They had three children.