The incredible story of how a disgraced Civil War general became one of the best-selling novelists in American history. Lew Wallace was making conversation with the other gentlemen in his sleeper car when a man in a nightgown appeared in the doorway. The train was bound for Indianapolis and the Third National Soldiers Reunion, where thousands of Union Army veterans planned to rally, reminisce, and march in a parade the New York Times would later describe as “the grandest street display ever seen in the United States.” It was Sept. 19, 1876, more than a decade since the Civil War...