Utah War

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Utah War
Part of the Mormon wars
American officers during the Utah War
Date March 1857 – July 1858 Location Utah Territory (present day Utah and Wyoming) Result Inconclusive[1] Utah War Peace Commission Brigham Young replaced as Governor of Utah Territory Full amnesty for charges of sedition and treason issued to the citizens of Utah Territory by President James Buchanan if they accepted US federal authority
Belligerents
United States	Deseret / Utah Native American allies
Commanders and leaders
President James Buchanan Governor Alfred Cumming General Albert S. Johnston	Gov. Brigham Young Gen. Daniel H. Wells Cap. Lot Smith
Units involved
United States Army 5th Infantry[2] 10th Infantry[2] B Battery (Phelps') of the 4th Artillery[2] 2nd Dragoons[2]	Nauvoo Legion Armed mormons
Strength
2,500–3,000	1,000
Casualties and losses
Civilians: 150 killed (120 in Mountain Meadows Massacre)[3]

The Utah War (1857–1858), also known as the Utah Expedition,^[4] the Utah Campaign,^[5] Buchanan's Blunder,^[6] the Mormon War,^[7] or the Mormon Rebellion,^[8] was an armed confrontation between Mormon settlers in the Utah Territory and the armed forces of the US government. The confrontation lasted from May 1857 to July 1858. The conflict primarily involved Mormon settlers and federal troops, escalating from tensions over governance and autonomy within the territory. There were several casualties, predominantly non-Mormon civilians. Although the war featured no significant military battles, it included the tragic Mountain Meadows Massacre, where Mormon militia members killed about 120 unarmed settlers traveling to California.

The resolution of the Utah War came through negotiations that permitted federal troops to enter Utah Territory in exchange for a pardon granted to the Mormon settlers for any potential acts of rebellion. This settlement significantly reduced the tensions and allowed for the re-establishment of federal authority over the territory while largely preserving Mormon interests and autonomy.