Today everyone knows the name of John Wilkes Booth, the notorious zealot who assassinated Abraham Lincoln. But in his lifetime, the killer was an actor who was well-known among fans of the theater, well-known but less famous and less admired than his brother Edwin. In the 1860s, Edwin Booth ranked among the greatest and most-respected stars of the stage. He lived in New York and sympathized with the Union cause, while his younger brother stomped the...