It sounds outlandish now, but the United States went to war with Mormons in the late 1850s. United States troops descended on the Utah Territory in 1857 due to growing concerns about actions carried out by the religious group and worries of sedition.
What led President Buchanan to send thousands of troops to the region? And how did those within the Utah Territory react?
The State of Deseret
After a number of deadly conflicts in Missouri and Illinois and the death of Joseph Smith, tens of thousands of Latter-day Saints moved to the Western United States, settling in Great Salt Lake basin during the late 1840s.
Due to population density, the Mormon religion and lifestyle reigned in the region. The Mormon people also successfully assimilated many Native Americans in the region within their religion and culture, with the groups living in relative harmony.
In 1849, members of the Church of Latter-Day Saints raised the ire of the U.S. Federal Government by creating the provisional State of Deseret out of newly acquired land from the Mexican Cession of 1848. Deseret had its own constitution and encompassed the majority of the modern Southwestern United States, covering Southern California, Nevada, Utah, Arizona, Colorado, and New Mexico.
In 1850, the United States responded by creating the Utah Territory out of roughly half the land encompassing the provisional state of Deseret, leading church leaders to abandon the idea. At the time, the Utah Territory covered most of modern Utah and Nevada, along with parts of Colorado and Wyoming. Federal appointees ruled the territory, with Mormon leader Brigham Young appointed to be the region's governor.
Within the Eastern United States, stories of bizarre Mormon behavior became commonplace. The group became a scapegoat for a number of problems, while newspapers and politicians told lurid stories of their practice of plural marriage.
The Drums of War
Eventually, tensions between Brigham Young, the Governor of the Utah Territory, and the United States government ran high.
Due to their prevalence in the region, Mormons wanted to govern the area under a set of religious laws instead of laws passed down by the U.S. Federal Government. Young also spoke of secession of his people from the United States and the creation of an independent country.
Brigham Young clashed with appointees made to help govern the Utah Territory, particular ones who did not practice the Mormon faith. James Buchanan took advantage of growing anti-Mormon sentiment, winning the 1856 Presidential Election on a campaign platform of "cleaning up" the Utah Territory.
Buchanan sent an expedition of several thousand soldiers to the Utah Territory in the early summer of 1857, ordering the group to set up a post in Utah. Their arrival sent the citizens of the Utah Territory into a frenzy, with Mormon leaders taking steps to begin defensive measures in case of an all-out attack made by the U.S. troops.
Brigham Young ordered the revival of the Nauvoo Legion — a Mormon militia which included almost every able-bodied man — and declared martial law in the Utah Territory.
After taking office, President Buchanan also made maneuvers to alter the political atmosphere in the Utah Territory. Buchanan appointed — without directly telling Governor Brigham Young — a new governor of the Utah Territory, Alfred Cumming. Young learned of the change when Cumming arrived in November of 1857, but Young refused to leave his position.
No direct conflicts occurred during the war, with the leaders of U.S. forces often cooling tempers in order to prevent the deaths of fellow Americans. The Nauvoo Legion carried out acts that would delay or perturb the army, but not kill them. Militia members burned grass, ran off the army's cattle, and performed other annoying acts, but never directly fought the U.S. troops.
The "war" itself only lasted a year, spanning the summer of 1857 to the summer of 1858. No official battles took place between Mormon militia members and U.S. troops; however, a number of casualties did occur.
Casualties of the Mormon War
Fears of occupation sent many of those living within the Utah Territory into a paranoid state. Paranoia likely led members of the Mormon militia to slaughter over 120 travelers, including a number of families, found in the Utah Territory in September of 1857. The spark for the attack, eventually known as the Mountain Meadows Massacre, is still unclear. A second attack took place in a month later, when Mormon settlers accused six Californians of being spies, and executed the men.
The Mormon War ended with a whimper as Congress found fault with Buchanan's handling of the situation, particularly the removal of Brigham Young from office. President Buchanan pardoned all Mormons involved as long as they subjected themselves to rule under the United States Federal Government. Young stepped down as Governor of the Utah Territory in 1858.
The top image is a painting of the Nauvoo Legion by C.C. Christensen and is within the public domain. Image of the constitution of Deseret is from the Brigham Young Library. Animated GIF of the changing Utah Territory by Mangoman88/CC. Sources linked within the article.