During the Civil War, Edison learned the emerging technology of telegraphy, and traveled around the country working as a telegrapher. But with the development of auditory signals for the telegraph, he was soon at a disadvantage as a telegrapher.
To address this problem, Edison began to work on inventing devices that would help make things possible for him despite his deafness (including a printer that would convert electrical telegraph signals to letters). In early 1869, he quit telegraphy to pursue invention full time.
Edison in Menlo Park
From 1870 to 1875, Edison worked out of Newark, New Jersey, where he developed telegraph-related products for both Western Union Telegraph Company (then the industry leader) and its rivals. Edison’s mother died in 1871, and that same year he married 16-year-old Mary Stillwell.
Despite his prolific telegraph work, Edison encountered financial difficulties by late 1875, but one year later—with the help of his father—Edison was able to build a laboratory and machine shop in Menlo Park, New Jersey, 12 miles south of Newark.
In 1877, Edison developed the carbon transmitter, a device that improved the audibility of the telephone by making it possible to transmit voices at higher volume and with more clarity.
That same year, his work with the telegraph and telephone led him to invent the phonograph, which recorded sound as indentations on a sheet of paraffin-coated paper; when the paper was moved beneath a stylus, the sounds were reproduced. The device made an immediate splash, though it took years before it could be produced and sold commercially.
Edison and the Light Bulb
In 1878, Edison focused on inventing a safe, inexpensive electric light to replace the gaslight—a challenge that scientists had been grappling with for the last 50 years. With the help of prominent financial backers like J.P. Morgan and the Vanderbilt family, Edison set up the Edison Electric Light Company and began research and development.
He made a breakthrough in October 1879 with a bulb that used a platinum filament, and in the summer of 1880 hit on carbonized bamboo as a viable alternative for the filament, which proved to be the key to a long-lasting and affordable light bulb. In 1881, he set up an electric light company in Newark, and the following year moved his family (which by now included three children) to New York.