The Mountain Meadows Massacre began on September 11, 1857 in Mountain Meadows, Utah where Mormon settlers and possibly Native Americans ambushed emigrants, a group of Arkansas farming families known as the Fancher party, traveling from Arkansas to California together with a group from Missouri that called themselves the "Missouri Wildcats". The ambushers killed around 120 men, women and older children; 17 of the younger children were spared and either returned to relatives in Arkansas or raised in Mormon families.
The travellers were besieged for four days, after which the Mormons reportedly promised safe passage if the migrants would surrender their weapons whereupon all but 17 young children were slaughtered. Brigham Young denied responsibility or knowledge until after the fact, but some critcs are unconvinced. John D. Lee a leader of the ambush, was excommunicated and later executed for his actions. While Lee admitted his complicity, he claimed he was a scapegoat for the many Mormon leaders responsible for the killings.
Initial reports said the attackers were a mixed group of Native Americans and Mormon settlers, but some researchers have disputed this, arguing that the attackers were largerly or entirely Mormon, some dressed as Native Americans.
The exact reasons for the massacre remain unclear and are in dispute. Some have argued that the area of the killings--now in southern Utah--was rife with religious violence. There were apparently rumors circulating in the region that among the Fancher party were members of a mob that killed Mormon founder Joseph Smith. This is based on statements reportedly made by the Fancher party members to non-Mormon traders on the Mormon trail. In addition, some reportedly claimed to be present at the assassination of Mormon Apostle Parley P. Pratt earlier that year. There were also rumors that the Federal Government was sending armed forces to take over Mormon settlements (see Johnston's Army), which contributed to a general distrust of outsiders and non-Mormons.
A pair of Latter-day Saint writers have recently been granted access to restricted documents in the archives of The Church of Jesus Christ of Latter-day Saints and will be publishing an account of the incident in 2003.