The following is text from Oxford professor Diarmaid MacCulloch's book "Christianity: The First Three-Thousand Years"...
This is an excerpt on 'Mormon' history from the chapter - "America: The New Protestant Empire"...
"There was plenty more creative reconstruction of Christianity in this most industrious and ingenious of Western societies. Spiritualism and the Church of Christ Scientist (products of yet more visionary women) both spread themselves from the USA through the Western world and beyond. Yet of all new departures amid the Second Awakenings, the most radical was the work of Joseph Smith, who may be seen as one of a chain of gifted young people in the nineteenth century applying their gifts to escaping the deprivation and social uncertainty in which they found themselves, both exploiting and inspired by the polychrome religious turbulence of their age. Hong Xiuquan, nine years younger than Smith, was another (see pp. 896-97). Smith's creation of a Heavenly Kingdom proved more long-lasting and less destructive than the Taiping, though likewise it brought him premature and violent death. Born in rural poverty in Vermont (not far from where Miller was beginning his married life) and pursued by poverty in his New York State childhood which deprived him of a decent education, Smith developed a keen interest in treasure-hunting amid a landscape haunted by Native American earthworks, devouring what conversation and what books (the Bible naturally among them) came his way. The boy, both dreamer and likeable extrovert, on the edge of so many cultures - Evangelicalism, self-improvement, popular history and archaeology, Freemasonry - constructed out of them a lost world as wonderful as that future paradise which confronted Hong Xiuquan.
Shortly after Smith's marriage in 1827, he had the first of a series of visits from a heavenly being in white, Moroni, who, according to Smith, was a former inhabitant of the Americas. Moroni took him to a secret store of inscribed golden plates. Smith was the only person definitely to view the plates, and their eventual removal was as angelic as their excavation; but the message which the semi-literate twenty-two-year-old translated into King James Bible English (his newly wed and devoted wife, Emma, and later two friends taking his dictation the other side of a curtain) was a formidably long text. It was published in 1830. The Book, written long before largely by Moroni's father, Mormon, was the story of God's people, their enemies and their eventual extinction in the fourth century CE. Yet these were no Israelites or Philistines, but Americans, and the enemies who destroyed them were the native peoples whom Smith's society called Red Indians. Now the spiritual descendants of Mormon were called to restore their heritage before the Last Days. Fawn M. Brodie, whose classic life of Smith earned her excommunication from the Mormon Church, saw the book of Mormon as one of the earliest examples of frontier fiction, the first long Yankee narrative that owes nothing to English literary fashions'. There was quite a genre of 'lost race' novels at the time. A century on, J.R.R. Tolkien's Lord of the Rings saga formed an English Catholic parallel, conscious or unconscious, to Smith's work. Tolkien's story-telling has many of the same characteristics as the Book of Mormon, although most people today would find Tolkien's prose a good deal more readable.
So with Smith's inspiration, the Mormons took shape: the Church of Jesus Christ of Latter-Day Saints, regarding itself as a restoration of an authentic Christianity otherwise lost. It moved en bloc, as so many utopian groups then did, to found a new ideal community on the frontier. The first stop in Ohio proved only one in a series of moves, because Smith and his leadership were prone to involve themselves deeply in state politics and risky business ventures, and their ambitions for power frightened and infuriated their neighbours. Finally Smith, now in charge of his own private army in Illinois, was fortified by fresh revelations to declare his candidacy in the 1844 presidential election. After further confrontations with the forces of unbelief, vigilantes shot him and his brother dead in an Illinois jail, while he was waiting trial on charges of intimidating a hostile local newspaper out of existence. Yet this was not the end for the Mormons. One of Smith's long-standing lieutenants, Brigham Young, Hong Rengen to Smith's Hong Xiuquan, seized the initiative and led the battered faithful on the final journey which would save their movement, at a cost of a hundred days' westwards travel by wagon to Utah. Young would have liked a territory to rival the Taiping conquest in scale, but he had to settle for the wilderness that the United States government allowed him. There was a long and stormy path to wary acceptance by wider American society, not least because of one of Smith's later revelations, posthumously released to the public in 1852, which had interesting resonances with the battles then going on in Protestant missions in Africa. He had been told that he must authorize polygamy.
Brigham Young reminisced in later life that he 'desired the grave' when first informed of this in 1843, but he later implemented it thoroughly in his own life, with as much public decorum as the nineteenth century would wish. As one of his less reverential biographers observed, Young's home in Salt Lake City 'resembled a New England household on a larger scale. Instead of one superficially forbidding lady in blacks or grays, there were nineteen of them. The widowed Mrs. Emma Smith, previously much tried by Prophet Smith's own clandestine accumulation of wives, married again; but not to a Mormon. It was 1890 before the mainstream of the Church laid polygamy aside and plenty of Mormons did not acknowledge their decision (some still do not, in carefully maintained seclusion in Utah and Arizona), but Utah still became a full state in 1896.
If polygamy proved a casualty of external nineteenth-century social assumptions, the end of the twentieth century saw another incursion of external liberal values when, in 1978, a revelation allowed men of Negro descent to take their place among whites in the universal priesthood allotted to all adult Mormon men - the original ban is of contested origin. Wholesome prosperity such as the youthful Smith might have envied has become a worldwide Mormon speciality, together with a systematic approach to spreading the message which has hardly been equaled in the Christianity which reserved itself the description Evangelical. The Mormons' doctrinal interest in genealogy, motivated by their belief in posthumous baptism of ancestors, has exercised a powerful appeal on those whose history is based on migration from another country. In the United States, its growth has been such that it has a good claim to be America's fourth-largest Christian denomination."