In 1847, the missionary Dr. Marcus Whitman, his wife, and 11 others were killed by members of the Cayuse tribe near present-day Walla Walla, Washington. A final response to years of frustration with the Whitmans, the event recorded in Western history as the 'Whitman Massacre' was a tipping point in American expansion, leading Congress to make the Oregon Country an official U.S. territory. Exposing the self-serving nature of American myth-making, Murder at the Mission reminds us of the dark realities of American expansion and of the lies that can persist when history is told only by victors.