Which black inventor patented fifty different devices, most of them dealing with the lubrication of machines, and successfully contested claims against the genuineness of his designs?

American engineer Elijah McCoy was born in Canada but became US citizen very young, and and made vital contributions in the United States after the Civil War such as in the progress of locomotives design and railroads in America, the automatic lubrication systems for steem engines and many other inventions among his 57 U. S. patents that made train travel more efficient.