For two years after Smith's death, conflicts escalated between Mormons and other Illinois residents.
To prevent war, Brigham Young led the Mormon pioneers (constituting most of the Latter Day Saints) to a temporary winter quarters in Nebraska and then, eventually (beginning in 1847), to what became the Utah Territory.
Having failed to build Zion within the confines of American society, the Mormons began to construct a society in isolation, based on their beliefs and values.
The cooperative ethic that Mormons had developed over the last decade and a half became important as settlers branched out and colonized a large desert region now known as the Mormon Corridor.
Colonizing efforts were seen as religious duties, and the new villages were governed by the Mormon bishops (local lay religious leaders).
The Mormons viewed land as commonwealth, devising and maintaining a co-operative system of irrigation that allowed them to build a farming community in the desert.

From 1849 to 1852, the Mormons greatly expanded their missionary efforts, establishing several missions in Europe, Latin America, and the South Pacific.
Converts were expected to "gather" to Zion, and during Young's presidency (1847–77) over seventy thousand Mormon converts immigrated to America.
Many of the converts came from England and Scandinavia, and were quickly assimilated into the Mormon community.
Many of these immigrants crossed the Great Plains in wagons drawn by oxen, while some later groups pulled their possessions in small handcarts.
During the 1860s, newcomers began using the new railroad that was under construction.

In 1852, church leaders publicized the previously secret practice of plural marriage, a form of polygamy.
Over the next 50 years, many Mormons (between 20 and 30 percent of Mormon families) entered into plural marriages as a religious duty, with the number of plural marriages reaching a peak around 1860, and then declining through the rest of the century.
Besides the doctrinal reasons for plural marriage, the practice made some economic sense, as many of the plural wives were single women who arrived in Utah without brothers or fathers to offer them societal support.

By 1857, tensions had again escalated between Mormons and other Americans, largely as a result of accusations involving polygamy and the theocratic rule of the Utah Territory by Brigham Young.
In 1857, U.S. President James Buchanan sent an army to Utah, which Mormons interpreted as open aggression against them.
Fearing a repeat of Missouri and Illinois, the Mormons prepared to defend themselves, determined to torch their own homes in the case that they were invaded.
The relatively peaceful Utah War ensued from 1857 to 1858, in which the most notable instance of violence was the Mountain Meadows massacre, when leaders of a local Mormon militia ordered the killing of a civilian emigrant party that was traveling through Utah during the escalating tensions.
In 1858, Young agreed to step down from his position as governor and was replaced by a non-Mormon, Alfred Cumming.
Nevertheless, the LDS Church still wielded significant political power in the Utah Territory.

At Young's death in 1877, he was followed by other LDS Church presidents, who resisted efforts by the United States Congress to outlaw Mormon polygamous marriages.
In 1878, the U.S. Supreme Court ruled in Reynolds v. United States that religious duty was not a suitable defense for practicing polygamy, and many Mormon polygamists went into hiding; later, Congress began seizing church assets.
In September 1890, church president Wilford Woodruff issued a Manifesto that officially suspended the practice of polygamy.
Although this Manifesto did not dissolve existing plural marriages, relations with the United States markedly improved after 1890, such that Utah was admitted as a U.S. state in 1896.
After the Manifesto, some Mormons continued to enter into polygamous marriages, but these eventually stopped in 1904 when church president Joseph F. Smith disavowed polygamy before Congress and issued a "Second Manifesto" calling for
For two years after Smith's death, conflicts escalated between Mormons and other Illinois residents. To prevent war, Brigham Young led the Mormon pioneers (constituting most of the Latter Day Saints) to a temporary winter quarters in Nebraska and then, eventually (beginning in 1847), to what became the Utah Territory. Having failed to build Zion within the confines of American society, the Mormons began to construct a society in isolation, based on their beliefs and values. The cooperative ethic that Mormons had developed over the last decade and a half became important as settlers branched out and colonized a large desert region now known as the Mormon Corridor. Colonizing efforts were seen as religious duties, and the new villages were governed by the Mormon bishops (local lay religious leaders). The Mormons viewed land as commonwealth, devising and maintaining a co-operative system of irrigation that allowed them to build a farming community in the desert.
From 1849 to 1852, the Mormons greatly expanded their missionary efforts, establishing several missions in Europe, Latin America, and the South Pacific. Converts were expected to "gather" to Zion, and during Young's presidency (1847–77) over seventy thousand Mormon converts immigrated to America. Many of the converts came from England and Scandinavia, and were quickly assimilated into the Mormon community. Many of these immigrants crossed the Great Plains in wagons drawn by oxen, while some later groups pulled their possessions in small handcarts. During the 1860s, newcomers began using the new railroad that was under construction.
In 1852, church leaders publicized the previously secret practice of plural marriage, a form of polygamy. Over the next 50 years, many Mormons (between 20 and 30 percent of Mormon families) entered into plural marriages as a religious duty, with the number of plural marriages reaching a peak around 1860, and then declining through the rest of the century. Besides the doctrinal reasons for plural marriage, the practice made some economic sense, as many of the plural wives were single women who arrived in Utah without brothers or fathers to offer them societal support.
By 1857, tensions had again escalated between Mormons and other Americans, largely as a result of accusations involving polygamy and the theocratic rule of the Utah Territory by Brigham Young. In 1857, U.S. President James Buchanan sent an army to Utah, which Mormons interpreted as open aggression against them. Fearing a repeat of Missouri and Illinois, the Mormons prepared to defend themselves, determined to torch their own homes in the case that they were invaded. The relatively peaceful Utah War ensued from 1857 to 1858, in which the most notable instance of violence was the Mountain Meadows massacre, when leaders of a local Mormon militia ordered the killing of a civilian emigrant party that was traveling through Utah during the escalating tensions. In 1858, Young agreed to step down from his position as governor and was replaced by a non-Mormon, Alfred Cumming. Nevertheless, the LDS Church still wielded significant political power in the Utah Territory.
At Young's death in 1877, he was followed by other LDS Church presidents, who resisted efforts by the United States Congress to outlaw Mormon polygamous marriages. In 1878, the U.S. Supreme Court ruled in Reynolds v. United States that religious duty was not a suitable defense for practicing polygamy, and many Mormon polygamists went into hiding; later, Congress began seizing church assets. In September 1890, church president Wilford Woodruff issued a Manifesto that officially suspended the practice of polygamy. Although this Manifesto did not dissolve existing plural marriages, relations with the United States markedly improved after 1890, such that Utah was admitted as a U.S. state in 1896. After the Manifesto, some Mormons continued to enter into polygamous marriages, but these eventually stopped in 1904 when church president Joseph F. Smith disavowed polygamy before Congress and issued a "Second Manifesto" calling for
Mormons