The American Civil War was one of the most harrowing conflicts in history. What many of us don't know is the key role that spies played on both sides of the Mason-Dixon Line during the four-year struggle. This secret war was waged by an intriguing lineup of participants: detective agency chief Allan Pinkerton, who was said to have thwarted a conspiracy to assassinate President-elect Abraham Lincoln; Elizabeth Van Lew, known as "Crazy Bet," the operator of a Union spy ring right in the heart of the Confederacy in Richmond, Virginia; and John Singleton Mosby, or the "Gray Ghost" as he was known, who created havoc by attacking Union troops behind their own lines - and disappearing into the countryside, seemingly without a trace. The Secret Civil War tells their stories and more in a compelling tale of espionage, daring, and in many cases, conflicting loyalties.