American George Washington Carver is probably the most prolific inventor . . . what he did with peanuts and sweet potatoes/yams.
My favorite has got to be J. B. Rhodes, who in 1899, invented the water closet.
Secondly, I am forever grateful for J. Standard who invented the refrigerator eight years (in 1891) before the modern toilet was available.
The contributions of African-Americans goes on and on. Thank God for their contributions to society!