After Joseph Smith and Brigham Young, Parley P. Pratt was the most influential figure in early Mormon history and culture. Missionary, pamphleteer, theologian, historian, and martyr, Pratt was perennially stalked by controversy--regarded, he said, "almost as an Angel by thousands and counted an Imposter by tens of thousands." Tracing the life of this colorful figure from his hardscrabble origins in upstate New York to his murder in 1857, Terryl...