"From the bestselling author of The Indispensables, the unknown and dramatic story of irregular guerrilla warfare that altered the course of the Civil War and inspired the origins of America's modern special operations forces. The Civil War is most remembered for the grand battles that have come to define it: Gettysburg, Antietam, Shiloh, among others. However, as bestselling author Patrick K. O'Donnell reveals in The Unvanquished, a vital shadow...