Marching 2,000 miles through a mostly uncharted American Southwest, the 500-man Mormon battalion was a pivotal force in fulfilling the national dream of Manifest Destiny. Their experiences, shared in this film through personal correspondence, journals and historical accounts, changed the face and fate of the American West.

The story opens in 1846 with a plan forged by two determined men, both looking west to secure new land for their people. In Council Bluffs, Iowa, LDS Church leader Brigham Young had resolved to leave the United States and create a Mormon settlement in the unknown lands of the American West. In Washington, D.C., U.S. President James K. Polk was courting a war with two foreign powers as he planned to expand the nation's reach to the Pacific Ocean.

The leaders' visions would converge over a mutual tradeoff. After being violently forced out of their homes in Illinois, the impoverished Mormons needed financial support to undertake a westward migration. Polk needed a loyal band of soldiers to fight a war with Mexico-and possibly Great Britain-in his push to fulfill his goal of Manifest Destiny. He also needed to squelch the potential for a Mormon alliance with Great Britain. In a deft move that would secure the western states while easing relations with Young's persecuted followers, the president called for a band of Mormons to march on California with U.S. General Stephen Kearney. By accepting the offer, Brigham Young would secure a government-sponsored westward migration along with the much-needed revenue from the soldiers' military compensation.