Richard Bowie Spikes was a prolific inventor with more than a dozen patents to his name. Primarily interested in automobile mechanics, Spikes also sought to improve the operation of items as varied as barber chairs and trolley cars.
https://www.google.com/amp/s/face2faceafrica.com/article/richard-spikes-the-blind-automobile-genius-who-invented-the-traffic-indicator-lights/amp
George Franklin Grant (September 15, 1846 – August 21, 1910) was the first African-American professor at Harvard. He was also a Boston dentist and an inventor of a wooden golf tee.
Learn more about Mr. Grant here: http://ivy50.com/blackhistory/story.aspx?sid=1/13/2009
Rebecca Lee Crumpler (1831–1895), the first Black woman in the United States to qualify as a doctor, opened her own medical clinic in Boston and dedicated herself to treating women and children who lived in poverty. She treated patients regardless of their ability to pay and often took no money for her work.
https://www.google.com/amp/s/www.medicalnewstoday.com/amp/articles/dr-rebecca-lee-crumpler-the-first-black-woman-md-in-the-us
Percy Julian– a civil rights activist, entrepreneur, and steroid chemist- played an essential role in developing many of the steroid-based medical drugs that are used today, including cortisone, hydrocortisone, and birth control pills. He is one of the first chemists to create pharmaceuticals that are plant-based. Although Percy Julian provided tremendous contributions to the world of medicine, there were many obstacles that he had to overcome to accomplish his goals.
https://www.pbs.org/wgbh/nova/video/percy-julian-20th-century-scientist/
Born in 1848, Lewis Latimer was the son of slaves who escaped in 1842. His slave owner captured him but a bunch of abolitionists fought for his freedom and won. Latimer served in the US Navy, receiving an honorable discharge.
In 1880, after moving to Bridgeport, Connecticut, Latimer was hired as the assistant manager and draftsman for the U.S. Electric Lighting Company owned by Hiram Maxim. Maxim was the chief rival to Thomas Edison. The light bulb at the time was composed of a glass bulb which surrounded a carbon wire filament, generally made of bamboo, paper, or thread. When the filament was burned inside of the bulb, it became so hot that it actually glowed.
Thus bypassing electricity into the bulb, Edison had been able to cause the glowing bright light to emanate within a room. Before this time most lighting was delivered either through candles or through gas lamps or kerosene lanterns. Maxim greatly desired to improve on Edison’s light bulb and focused on the main weakness of Edison’s bulb – their short life span (generally only a few days.) Latimer set out to make a longer-lasting bulb.
Latimer devised a way of encasing the filament within a cardboard envelope which prevented the carbon from breaking and thereby provided a much longer life to the bulb and hence made the bulbs less expensive and more efficient. This enabled electric lighting to be installed within homes and throughout streets. 
Latimer’s abilities in electric lighting became well known and soon he was sought after to continue to improve on incandescent lighting as well as arc lighting. Eventually, as more major cities began wiring their streets for electric lighting, Latimer was dispatched to lead the planning team. He helped to install the first electric plants in Philadelphia, New York City, and Montreal and oversaw the installation of lighting in railroad stations, government buildings, and major thoroughfares in Canada, New England, and London.
