The historical development of Mormonism may be traced back to the revelatory experiences of Joseph Smith, who claimed to have had multiple encounters with heavenly beings, beginning in 1820. Smith, the son of unsuccessful and migratory farmers who at the time lived in Palmyra in western New York, had this initial experience when he was 14 years old.
Troubled by the competing religious claims and conflicting scriptural views expressed in the camp meetings and revivals that passed through his hometown as part of the Second Great Awakening, Smith asked God directly which church he should join. According to Smith's accounts of the event, he was visited by God the Father and Jesus Christ. Jesus told Smith that the true Christian church was no longer on earth and advised him not to join any of the sects then vying for members in his area.
In 1823, Smith claimed to have spoken with another heavenly visitor named Moroni. This angel, according to Smith, explained that he had been a Christian prophet who lived in the western hemisphere in the 5th century C.E. He had been the last prophet in a civilization that descended from a man named Lehi who had been called by God to leave Jerusalem and travel to the Americas in the 7th century B.C.E. Moroni and his predecessors had kept a history engraved on gold plates, which Smith was to recover and translate.
In 1830, Smith published The Book of Mormon and formally organized a church that was called, at that time, The Church of Christ. In late 1830, on a mission trip to Missouri, several Mormons passed through the small town of Kirtland, in northeast Ohio. While in Kirtland, the missionaries met Sidney Rigdon, a local restorationist preacher who converted to Mormonism in 1830 and influenced many of his flock to follow suit.
The growth of Mormonism in the Kirtland area was so rapid and successful that Smith moved the headquarters of the Church there in early 1831. The Mormons would maintain a headquarters at Kirtland until 1838, during which time they constructed a temple and published a collection of the revelations received by Smith.
Later in 1831, Smith told his followers that God had revealed to him the location of the New Jerusalem spoken of in the Bible. Smith identified the site as Independence, Missouri, and he called on some of the Church's members to leave Ohio and set up a second headquarters in "Zion." Conflicts with Missouri locals over a variety of political, economic, and social issues soon turned deadly for the Mormons. In the fall of 1833, the Mormons were forced to leave Independence, and they established several short-term settlements in Clay, Caldwell, and Daviess counties in Missouri.
In 1837, the Mormon community at Kirtland internally collapsed. The failure of the Church's financial institution and a major schism within the Church's leadership structure over Smith's role in the banking fiasco led to Smith's decision to leave Kirtland for the far west in Caldwell County. Not long after, tensions mounted again. In 1838, the Mormons again experienced bloody conflicts with local militia units, which led the governor of the state to order that the Mormons must either be driven from the state or "exterminated."
The main body of Mormons, both those fleeing Missouri and those coming from Kirtland, spent the winter of 1838-1839 in the city of Quincy, Illinois, until Joseph Smith founded yet another city, this time on the banks of the Mississippi River in western Illinois. Smith arranged to purchase 18,000 acres of land in Hancock County, Illinois, and Lee County, Iowa. The Mormons purchased a small town called Commerce on the Illinois side of the Mississippi River, and made it the focal point of their new settlement effort. Joseph Smith re-christened the town Nauvoo, which Smith suggested was a Hebrew name denoting a place of rest or refreshing.
Having learned from experiences in Missouri, Smith sought, and was granted, significant judicial and political power over his new settlement. The secure environment allowed Mormonism to expand and develop theologically and politically. In the years between 1839, when the Mormons arrived in Nauvoo, and 1844, when Smith was murdered, he introduced polygamy, eternal marriage, the temple endowment, the secret Council of Fifty, and ran for president of the United States. The Church also continued its tradition of newspaper publishing with the religiously oriented Times and Seasons and the more politically inclined Mormon Wasp and the Nauvoo Neighbor.
A newspaper led to Smith's downfall. Dissidents in Nauvoo who objected to his growing political power and disturbing new doctrines like polygamy published a call for reform in the Nauvoo Expositor. Fearing it would rile the growing number of opponents outside the city, Smith and the city council closed the paper. Outraged at this affront, his enemies had him arrested. While awaiting trial in nearby Carthage, he was killed by a mob.