The Great Utah War was a conflict between the United States of America and the Mormon settlers of Utah Territory beginning in 1857. Originally President James Buchanan sent an expedition of 2500 soldiers to suppress what he termed to be a "rebellion" in the Territory. These were meant to accompany Alfred Cumming whom Buchanan had selected to replace Mormon Church President Brigham Young as governor. They were also meant to build a post in Utah and function as a posse comitatus under the direction of the new governor. However, Buchanan never informed Young of his intentions, and the Latter-day Saints, fearful of annihilation by a federal army, blocked the Expedition's entrance into the Salt Lake Valley.