When the Latter-day Saints first appealed to the U.S. Government in 1839–1840 for redress of wrongs committed against them in Missouri, Church President Joseph Smith said, “About 491 individuals gave in their claims against Missouri, which I submitted to Congress. . . .” More than 200 of these same claims or affidavits plus other important original documents relating to Mormon history in Missouri have been uncovered by the Institute of Mormon Studies at the National Archives in Washington, D.C. These affidavits, sworn to by members of The Church of Jesus Christ of Latter-day Saints shortly after they were driven from Missouri in 1839, constitute a veritable gold mine of firsthand accounts covering the 1831–1839 period of LDS Church history on the western frontier.