Joseph Smith, the founder and leader of the Church of Jesus Christ of Latter-day Saints (more commonly known as Mormonism), is murdered along with his brother Hyrum when a mob breaks into a jail where they are being held in Carthage, Illinois.

Born in Vermont in 1805, Smith claimed in 1823 that he had been visited by a Christian angel named Moroni who spoke to him of an ancient text that had been lost for 1,500 years. The holy text, supposedly engraved on gold plates by a Native American historian in the fourth century, related the story of Israelite peoples who had lived in America in ancient times. During the next several years, Smith dictated an English translation of this text to his wife and other scribes, and in 1830 The Book of Mormon was published. In the same year, Smith founded the Church of Christ—later known as the Church of Jesus Christ of Latter-day Saints—in Fayette Township.

The religion rapidly gained converts, and Smith set up communities in Ohio, Missouri, and Illinois. However, the Christian sect was also heavily criticized for its unorthodox practices, such as polygamy. In 1844, Smith announced his candidacy for the presidency of the United States. Although he did not have great enough appeal to win, the idea of Smith as president increased anti-Mormon sentiment. A group of dissenting Latter-day Saints began publishing a newspaper that was highly critical of the practice of polygamy and of Smith’s leadership; Smith had the press destroyed. The ensuing threat of violence prompted Smith to call out a militia in the town of Nauvoo, Illinois. He was charged with treason and conspiracy by Illinois authorities and imprisoned with his brother Hyrum in the Carthage city jail. On June 27, 1844, a mob stormed in and murdered the brothers.

Two years later, Smith’s successor, Brigham Young, led an exodus of persecuted Latter-day Saints from Nauvoo along the western wagon trails in search of religious and political freedom. In July 1847, the 148 initial pioneers reached Utah’s Valley of the Great Salt Lake. Upon viewing the valley, Young declared, “This is the place,” and the pioneers began preparations for the tens of thousands of migrants who would follow them to settle there.