In 1835, Joseph set apart twelve men as the Quorum of the Twelve Apostles, and confirmed himself as supreme authority in the church. At the time, Joseph saw the primary role of the Quorum of the Twelve as the evangelization of the world.

Joseph began work on the Book of Abraham, inspired by ancient Egyptian papyri he had purchased from Michael H. Chandler. This text included a passage in which Pharaoh was forbidden to receive the priesthood, because he was a descendent of Ham.

In 1835, Joseph Smith likely took a seventeen-year-old girl named Fannie Alger as a plural wife. This was also the year that the church made its first of numerous public denials that polygamy was believed in or practiced by any of its members, and threatened to excommunicate any involved in polygamous relationships. Though Joseph had been privately teaching and practicing polygamy since 1831, the church would not openly avow it until 1852.