Elijah McCoy, inventor
May 2, 1843(4?)-October 10, 1929
The Real McCoy: The Life of an African-American Inventor by Wendy Towle, illustrated by Wil Clay (Scholastic, paper, 1995)
An engineer, McCoy invented (among other things) an automatic lubricator for trains and heavy machinery. It was so much better than what was in common use that people insisted on “the real McCoy.”
A short bio on a web site hosted by Northern California Council of Black Professional Engineers highlights McCoy.