Lewis H. Latimer was born in 1848 in Chelsea, Massachusetts. Latimer was one of the first major African-American inventors, responsible for items such as the first water closet (or toilet) for railroad cars in 1874, as well as the forerunner to the air conditioner in 1886. He was most noted for his work with Thomas Edison, and for making electric light available to the world.
As an accomplished draftsman, Latimer first worked as an assistant to Alexander Graham Bell, who hired Latimer to draw plans for his telephone invention. Bell was in a race to have his telephone patented first. By working with him late into the night, Latimer was able to provide Bell with the blueprint drawings he needed to file his telephone patent on February 14, 1876.
In 1884, Latimer became an engineer at the Edison Electric Light Company, joining Thomas Edison's elite research team, Edison's Pioneers, which had only 28 charter members. Latimer was the only African-American in this prestigious group. Here he made his most important scientific contributions, improving the light bulb invented by Edison, and inventing a manufacturing process for the carbon filament in 1882. Edison's light bulb was illuminated by an electrified filament made of paper, which burned out quickly. Latimer created a light bulb with a filament made of the much more durable carbon. Latimer sold the patent for the incandescent electric light bulb with carbon filament to the United States Electric Company in 1881. Latimer also developed and patented the threaded socket for his improved bulb, though then it was made of wood.
Latimer shared a patent for the Maxim electric lamp, and made other contributions. He later supervised the installation of electric street lights in New York City, Philadelphia, Montreal, and London, making possible the widespread use of electric light.
Edison was impressed with Latimer and encouraged him to write a book. This was the first book on electric lighting, Incandescent Electric Lighting: A Practical Description of the Edison System, published in 1890.