Depiction of Mountain Meadows massacre.
As a territory, Utah came under the direct control of Congress. Mormon leader Brigham Young was appointed territorial governor, but he resented any infringement on his authority. Young's leadership provoked the national government to declare the territory in "rebellion," bringing U.S. troops to Utah in a conflict known as the Mormon War.
Following the horror of a Mormon-led massacre of 120 people in a westward-bound wagon train at Mountain Meadow in fall 1857, public opinion regarding the church deteriorated. Deseret's prospects for statehood seemed dim.
During the Civil War, the U.S. government shifted its attention from the Mormons. President Abraham Lincoln told a Mormon representative to Washington, D.C., "You go back and tell Brigham Young that if he will let me alone I will let him alone."
In this period of Mormon isolation, Young, having given up his governorship, built the insularity of the Mormons against the territory's encroaching non-Mormon population.
"[The Mormon leadership] send[s] a petition signed by thousands of people from Utah, saying that they will no longer obey any laws of Congress that they don't like. They run out virtually every non-Mormon federal official in the territory."-- Will Bagley, historian
"The South is making continual sounds towards secession. The issue is slavery and states' rights -- and the person that's dealing with it is a president by the name of James Buchanan. Buchanan declares the Utah Territory in rebellion, and he marches 20 percent of the entire United States Army to the West to subdue the rebellion."-- Ken Verdoia, journalist
See a bonus video segment on the unresolved questions of the Mountain Meadows massacre.