Mormon Battalion

The Mormon Battalion, the only religiously based unit in United States military history, served from July 1846 to July 1847 during the Mexican–American War of 1846–1848. The battalion was a volunteer unit of between 534 and 559Latter-day Saints men, led by Mormon company officers commanded by regular U.S. Army officers. During its service, the battalion made a grueling march of nearly 2,000 miles from Council Bluffs, Iowa, to San Diego.

The battalion’s march and service supported the eventual cession of much of the American Southwest from Mexico to the United States, especially the Gadsden Purchase of 1853 of southern Arizona and New Mexico. 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.

At the time they enlisted, members of The Church of Jesus Christ of Latter-day Saints were seeking U.S. government aid for their migration west to the Rocky Mountains and Salt Lake Valley, despite having their previous petitions for redress of grievances denied. Under continued religious persecution, they had fled Nauvoo, Illinois, on February 4, 1846 across the Mississippi River. They camped among the Potawatomi Indians near present-day Council Bluffs, Iowa.

Brigham Young, the President of the Quorum of the Twelve Apostles, sent Elder Jesse C. Little to Washington, D.C., to seek assistance from the federal government for the Mormon Pioneers fleeing from the Illinois mobs. Little arrived in Washington D.C. on May 21, 1846, only eight days after Congress had declared war on Mexico. Pennsylvania Army officer and attorney Thomas L. Kane offered the Mormons his advice and assistance. Politically well connected through his jurist father, Kane provided letters of recommendation and joined Little in Washington, D.C. The two called on the secretary of state, secretary of war, and President James K. Polk. After several interviews in early June 1846, President Polk agreed to Little's offer if "a few hundred" men enlisted. On June 2, 1846, President Polk wrote in his diary: "Col. [Stephen W.] Kearny was. . . authorized to receive into service as volunteers a few hundred of the Mormons who are now on their way to California, with a view to conciliate them, attach them to our country, and prevent them from taking part against us."

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