Union cavalryman Boston Corbett became a national celebrity after killing John Wilkes Booth, but as details of his odd personality became known, he also became the object of derision. Over time, he was largely forgotten to history, a minor character in the final act of Booth's tumultuous life. And yet Corbett led a fascinating life of his own, a tragic saga that weaved through the monumental events of nineteenth-century America. Corbett was...