Seventies president Levi W. Hancock enlists as the first actively serving general authority to participate in a U.S. war. Young promises the battalion on 18 Jul that "you will have no fighting to do," which proves true. A sick detachment would siphon off nearly 275 Mormons to Pueblo, Colorado, where they would be discharged and arrive in Salt Lake Valley on 29 Jul 1847. The rest would march along the Mexican border to San Diego where most would be discharged in Los Angeles on 16 Jul 1847.
[Quinn, D. Michael, The Mormon Hierarchy: Origins of Power, Appendix 7: Selected Chronology of the Church of Jesus Christ of Latter-day Saints, 1830-47, http://amzn.to/origins-power]