The Year of Decision 1846 tells many fascinating stories of the U.S. explorers who began the western march from the Mississippi to the Pacific, from Canada to the annexation of Texas, California, and the southwest lands from Mexico. It is the penultimate book of a trilogy which includes Across the Wide Missouri (for which DeVoto won both the Pulitzer and Bancroft prizes) and The Course of Empire. DeVoto's narrative covers the expanding Western frontier, the Mormons, the Donner party, Fremont's exploration, the Army of the West, and takes readers into Native American tribal life.