William Jackson was a slave in the home of Confederate president Jefferson Davis during the Civil War. It turns out he was also a spy for the Union Army, providing key secrets to the North about the Confederacy. William Jackson, a slave, listened closely to Jefferson Davis' conversations and leaked them to the North. Jackson was Davis' house servant and personal coachman. He learned high-level details about Confederate battle plans and movements because Davis saw him as a "piece of furniture" -- not a human, according to Ken Dagler, author of "Black Dispatches," which explores espionage by America's slaves.