 After being taught by Caroline Barnes Crosby and Jonathan Crosby, early Mormon converts, the Pratts converted to Mormonism and joined the Latter Day Saints in Indiana, Missouri, and later moved to Nauvoo, Illinois.Years later, the Pratts persuaded the Crosbys to join them in missionary work in the Pacific Islands.While working aboard a whaling ship as a young man, Pratt had jumped ship in Hawaii and spent several months living near the village of Honolulu; he was one of the first men of European descent to live in the Hawaiian islands.