Mormon Pioneers arrived in the Salt Lake Valley on July 24, 1847, and immediately began planting and irrigating. Under direction of the church organization, the settlers cooperated to tame the land and its natural resources. At this time, present-day Utah was in Mexican territory.
By 1850, the outlying regions of Bountiful, Farmington, Ogden, Tooele, Provo, and Manti were settled.
Two kinds of colonizing efforts took place: directed settlements and undirected settlements. In directed settlements, colonies were planned, organized, and dispatched by the Church. Companies were appointed and equipped to explore the area, people were appointed to colonize it, and a leader was appointed. The Church gave instructions on the mission of the colony, whether to raise crops, assist Indians, mine coal, or serve as a way station for groups on the trail to California.
Non-directed settlements were founded by individuals, families, and neighborhood groups without direction from the Church. Most of the Wasatch Front communities were non-directed. Although Church leaders did not commission these settlements, they encouraged them, and quickly established wards when the population was great enough to justify them.
When the Mexican War ended in February 1848, the land became part of the United States. The Mormons proposed creating the State of Deseret, but Congress would not admit them to the Union. Instead, the federal government created the Territory of Utah, with Brigham Young as the first territorial governor.
In 1857, President James Buchanan sent a military force to Utah based on false reports of a Mormon rebellion against federal authority. The Utah Expedition was led by General Albert Sidney Johnston. This was part of a conflict known as the Utah War, which ended with only limited bloodshed.
More than 60,000 Mormons had come to the territory by the time the first transcontinental railroad was completed at Promontory, Utah in May of 1869.
After the Church announced the abandonment of polygamy in 1890, Congress finally granted statehood to the people of Utah on January 4, 1896.
Brief History of Utah, Utah History to Go, by Ron Rood and Linda Thatcher
History, by S. George Ellsworth
Colonization of Utah, Utah History Encyclopedia, by Leonard J. Arrington