History of Mormons in California.

This is from the video "More Precious Than Gold." The Mormon Battalion was the only religious "unit" in American military history serving from July 1846 to July 1847 during the Mexican-American War. They provided funds from their salaries and allowances to assist the Mormon exodus west, such as part of their clothing allowances they provided to Brigham Young to help finance the Latter-day Saint's move to the Salt Lake Valley.
The battalion was a volunteer unit of 500 soldiers, nearly all Mormon men with regular army officers in command and key staff positions along with Mormon company officers. The battalion made a grueling march from Council Bluffs, Iowa to San Diego, California. The Mormon Battalion were mostly members of The Church of Jesus Christ of Latter-day Saints who were fleeing religious persecution in Nauvoo, Illinois. The battalion's march and service was instrumental in helping secure new lands in several Western states, especially the Gadsden Purchase of 1853 of much of southern Arizona. The march also opened a southern wagon route to California. Veterans of the battalion played significant roles in America's westward expansion in California, Utah, Arizona and other parts of the West.
President of the Quorum of the Twelve Apostles, Brigham Young, sent Elder Jesse C. Little to Washington, D.C. to seek assistance from the federal government for the Mormon trek west. After several interviews with President James Polk in early June 1846, the offer to enlist some 500 men after the Mormons arrived in California was accepted. Yet, orders through military channels were misread and an army officer went to the Mormon camps in Iowa to enlist men into a battalion consisting of all Mormons.
The battalion was mustered into volunteer service on July 16, 1846 by Captain James Allen of the famous 1st U.S. Dragoons. Dispatched by Colonel (later Brigadier General) Stephen Kearny, Allen met no success in recruiting until Brigham Young and other members of the Twelve gave public approval. Eventually some 500 men volunteered into this unique "federal" unit, which was not structured as a more typical militia or state volunteer organization. Several large families, some soldier's wives and a number of teen age boys accompanied the battalion, making it appear more as a pioneer party than a military force. The Mormon Battalion would be part of the Army of the West under General Kearny, a tough and seasoned veteran, that would have two regiments of Missouri volunteers, a regiment of New York volunteers who would travel by ships to California, artillery and infantry battalions, Kearny's own 1st US Dragoons, and the battalion of Mormons.
The Mormon Battalion arrived in San Diego, California on January 29, 1847 after a march of some 1,900 miles from Iowa. For the next five months until their discharge on July 16, 1847 in Los Angeles, the battalion trained and also performed occupation duties in several locations in southern California. The most significant service the battalion provided in California and during the war, was as a reliable unit under Cooke that General Kearny could rely on to block Fremont's mutinous bid to control California. The construction of Fort Moore was one measure Cooke employed to protect legitimate military and civil control under Kearny. Some 22 Mormon men died from disease or other natural causes during their service. About 80 of the men re-enlisted for another six months of service.
A few of the men escorted John C. Fremont back east for his court-martial.
A few discharged veterans worked in the Sacramento area for James W. Marshall at Sutter's Mill. Henry Bigler recorded the actual date, January 24, 1848, in his diary (now on display at the Huntington Library in San Marino, CA) when gold was discovered. This gold find started the California Gold Rush the next year.