In the late 1820s, Joseph Smith, founder of the Latter Day Saint movement, announced that an angel had given him a set of golden plates engraved with a chronicle of ancient American peoples, which he had a unique gift to translate.
In 1830, he published the resulting narratives as the Book of Mormon and founded the Church of Christ in western New York, claiming it to be a restoration of early Christianity.
After escaping state custody in 1839, Smith directed the conversion of a swampland into Nauvoo, Illinois, where he became both mayor and commander of a nearly autonomous militia.
Under Brigham Young, the LDS Church orchestrated a massive overland migration of Latter-day Saint pioneers to Utah, by wagon train and, briefly, by handcart.
In its remote settlement, the church governed civil affairs and made public its practice of plural marriage (polygamy).
Eventually, the church issued a manifesto discontinuing polygamy, which paved the way to Utah statehood and realignment with mainstream American society.