Invention: Dry Scouring
Thomas Jennings was the first African American to receive a patent, on March 3, 1821 (U.S. patent3306x). Thomas Jennings' patent was for a dry-cleaning process called "dry scouring". The first money Thomas Jennings earned from his patent was spent on the legal fees (my polite way of saying enough money to purchase) necessary to liberate his family out of slavery and support the abolitionist cause.
Under the United States patent laws of 1793 and 1836, both slaves and freedman could patent their inventions. However, in 1857, a slave-owner named Oscar Stuart patented a "double cotton scraper" that was invented by his slave. Historical records only show the real inventor's ... inventors.about.com