" a religious book he had written several years ago called The Truth: A Companion to the Bible. The publicity it would bring the book, he believed, was one of the principal reasons God wanted him to assassinate the president. “Two points will be accomplished,” he wrote. “It will save the Republic, and create a demand for my book, "

― Candice Millard , Destiny of the Republic: A Tale of Madness, Medicine and the Murder of a President