The Utah War, 1857-1858, was a costly, disruptive and unnecessary confrontation between the Mormon people in Utah Territory and the government and army of the United States. It resulted from misunderstandings that transformed a simple decision to give Utah Territory a new governor into a year-long comedy of errors with a tragic potential. Had there been transcontinental telegraphic communications at the time, what has been referred to as "Buchanan's Blunder" almost certainly would not have occurred.
Sensitive to Republican charges that Democrats favored the "twin relics of barbarism--polygamy and slavery," President James Buchanan moved quickly after his inauguration to find a non-Mormon governor for Utah. Then, apparently influenced by reports from Judge W.W. Drummond and other former territorial officials, he and his cabinet decided that the Mormons would resist the replacement of Governor Brigham Young. So, without investigation, the contract for mail service to Utah was canceled and 2,500-man military force was ordered to accompany Alfred Cumming to Great Salt Lake City.