James Allen's study of William Clayton is one of the most important Mormon biographies of our time. There are several reasons for this. The first has to do with the specimen nature of Clayton's life. Although Professor Allen prefers to focus on him as a study in discipleship rather than as a sample Mormon, the time period involved necessarily gives Clayton representative significance. During his years as a Church member, 1838–79, he witnessed many of Mormonism's most significant historical events. He was part of the impressive harvest of English converts brought into the Church in the late 1830s and 1840s. He participated in the saga of migration across the Atlantic to the Mormon Zion. He lived in Nauvoo and saw the Saints lose their prophet-leaders through violence. Clayton was a part of the vanguard of pioneers who first crossed the plains and entered the Salt Lake Valley. He contributed to growth of the Latter-day Saint commonwealth under the leadership of Brigham Young. And he saw the coming of the railroad and the commencement of the national crusade against Mormon polygamy.