Info provided by Black American History:
Lewis Howard Latimer was born in 1848 in Massachusetts. His mother and father were runaway slaves that eventually gained their freedom through the help of abolitionists. In 1863, he joined the U.S. Navy at the age of 15. After being honorably discharged, Latimer got his start as an office boy with patent law firm Crosby Halstead & Gould in 1865. Recognizing his potential, his employer would promote him to head draftsman, helping to create technical drawings for patents.
Soon enough he started making his own contributions. In 1874, he co-patented an improved toilet system for mobile cars. In 1876, Latimer was hired by Alexander Graham Bell to draft patent drawings for Bell’s telephone.
However, his most notable contribution was receiving a patent in 1881 for the “Process of Manufacturing Carbons.” Latimer would later be hired by Thomas Edison in 1884 and go on to invent the carbon filament under his employ. This technology was improvement over Edison’s paper filament that burned too quickly, improving efficiency, cost, & availability.
source: Black American History