While traveling to visit family in western New York, Pratt had the opportunity to read a copy of the Book of Mormon owned by a Baptist deacon. Convinced of its authenticity, he traveled to Palmyra, New York and spoke to Hyrum Smith at the Smith home. He was baptized in Seneca Lake by Oliver Cowdery on or about 1 September 1830, formally joining the Latter Day Saint church (Mormons). He was also ordained to the office of an elder in the church. Continuing on to his family's home, he introduced his younger brother, Orson Pratt, to Mormonism and baptized him on 19 September 1830.
This biography was written by Parley and published posthumously.