A couple of weeks ago in Sunday School, a middle-aged woman shared her conversion story to Mormonism. Born and raised a Methodist, she noted that she always felt like something was lacking. When she discovered Mormonism, she explained, “it was like Methodism, only more.”

I smiled to myself as she said this, recognizing in her own conversion narrative a common refrain that dominates the autobiographical writings of her 19th century predecessors. Among the first generation of converts to Mormonism, roughly one-third of them came from Methodist backgrounds, including Emma Smith, Brigham Young, and John Taylor. Even Joseph Smith remembered being “somewhat partial to the Methodist sect” and feeling “some desire to be united with them” before his own visionary...