A spy in the South during the American Civil War? How about even better–a spy in Jefferson Davis’s Confederate White House? Got any military papers or maps lying around?

The beauty is that no one suspected a black spy working as a domestic servant in the pro-slavery South.
That was foolish, for the super-intelligent Mary Bowser gathered information to send it to the North. The ring of spies in which she participated was cited by Union General Ulysses Grant as providing critical information to fight the war.
After the Civil War ended, she went on to teach freed slaves across the South. But not much is known about her. As a former spy, she had reason to be careful.
Still, even the U.S. Central Intelligence Agency honors her. The image comes from them.
Want more? Check out the New York Times article.
Thanks to the Sam Maggs and her book Wonder Women.