The Mormon Rebellion
The Utah War (1857–1858), also known as the Utah Expedition, Utah Campaign, Buchanan’s Blunder,[ the Mormon War, or the Mormon Rebellion was an armed confrontation between Mormon settlers in the Utah Territory and the armed forces of the United States government. The confrontation lasted from May 1857 to July 1858. There were some casualties, mostly non-Mormon civilians. The war had no notable military battles.
~ Summary from Wikipedia