The first Mormon pioneers make their exodus from Nauvoo, Illinois, westward towards Salt Lake Valley.

The Mormon pioneers were members of the Church of Jesus Christ of Latter-day Saints, also known as Latter-day Saints, who migrated beginning in the mid-1840s until the late-1860s across the United States from the Midwest to the Salt Lake Valley in what is today the U.S. state of Utah. At the time of the planning of the exodus in 1846, the territory comprising present-day Utah was part of the Republic of Mexico, with which the U.S. soon went to war over a border dispute left unresolved after the annexation of Texas. The Salt Lake Valley became American territory as a result of the Treaty of Guadalupe Hidalgo, which ended the war.

Nauvoo is a small city in Hancock County, Illinois, United States, on the Mississippi River near Fort Madison, Iowa. The population of Nauvoo was 950 at the 2020 census. Nauvoo attracts visitors for its historic importance and its religious significance to members of several groups: The Church of Jesus Christ of Latter-day Saints; the Community of Christ, formerly the Reorganized Church of Jesus Christ of Latter-day Saints (RLDS); other groups stemming from the Latter Day Saint movement; and the Icarians. The city and its immediate surrounding area are listed on the National Register of Historic Places as the Nauvoo Historic District.

Salt Lake Valley is a 500-square-mile (1,300 km²) valley in Salt Lake County in the north-central portion of the U.S. state of Utah. It contains Salt Lake City and many of its suburbs, notably Murray, Sandy, South Jordan, West Jordan, and West Valley City; its total population is 1,029,655 as of 2010.