Across the Plains in 1844 by Catherine Sager is among the most gripping firsthand accounts of pioneer life in the American West ever written. It is also a key primary document supporting the events of the Whitman Massacre. On November 29, 1847, Marcus Whitman, a doctor, and Narcissa Whitman, his wife, and twelve other members of the Waiilatpu Mission in the Oregon Territory were murdered by a small contingent of the Cayuse Indians. The killings became known as the "Whitman Massacre." Earlier fur traders had threatened Native people with infectious disease, so when measles spread to the mission in the mid-1840s, decimating the nearby Cayuses, the Indians blamed Whitman. Plateau Indians usually did not kill shamans for failing to cure patients, but they believed that excessive amounts of spiritual power could inspire murderous intentions. After slaughtering the Whitmans, the Cayuses took dozens of settlers hostage, mostly women and children, including Catherine Sager. Across the Plains in 1844 is Sager's page-turning account of the initial journey west, the measles outbreak, the massacre of the Whitmans, Sager's subsequent capture, and her eventual emancipation.