The incident at Simpson's Hollow was one of only three significant engagements of the Utah War and played a key role in the conflict. The Utah War of 1857-1858 grew from poor communication between the U.S. Government and the Utah Territory over Brigham Young's authority as both governor of Utah and head of the Church of Latter Day Saints. President Buchanan appointed Alfred Cumming as the new governor, but fearing that Utah's citizens would not calmly accept Young's replacement, he canceled mail service to Utah and sent a military force of 2,500 men to escort Cumming safely to Salt Lake City. Captain Lew Simpson and his troops were part of this force traveling to Utah on the Oregon Trail. Because Young and other Mormon leaders had not been informed of the administrative change, they believed the army intended religious persecution, and Young deployed the Utah Militia, known as the Nauvoo Legion, to slow the U.S. troops. In October 1857, a wagon train under Simpson's command was surrounded by the Utah Militia and forced to surrender its wagons. Led by Lot Smith, the Militia released the livestock and burned all but one supply wagon, causing damages estimated at more than $85,000. The Militia also burned two other wagon trains, forcing the entire army to spend the winter near the recently burned Fort Bridger. In the spring, Thomas L. Kane negotiated a settlement that allowed U.S. troops to enter Salt Lake City peacefully, and Young stepped down and established a diplomatic relationship with Governor Cumming.