Carbon-filament Light Bulb
Thomas Edison often gets the credit for inventing the light bulb, but in reality, dozens of inventors were working to perfect commercial lighting. One of those inventors was Lewis Latimer.
Latimer was hired at a law firm that specialized in patents in 1868; while there, he taught himself mechanical drawing and was promoted from office boy to draftsman. In his time at the firm, he worked with Alexander Graham Bell on the plans for the telephone. Latimer then began his foray into the world of light. Edison was working on a light bulb model with a paper filament (the filament is the thin fiber that the electric current heats to produce light). In Edison's experiments, the paper would burn down in 15 minutes or so, rendering the bulb unrealistic for practical use.
It was Latimer who created a light bulb model that used a carbon filament, which lasted longer and made light bulb production cheaper. Because of Latimer's innovation, more people could afford to light their homes. Latimer also received patents for a water closet on railroad cars and a predecessor to the modern air conditioner.