In April 1844 the Sager family took part in the great westward migration and started their journey along the Oregon Trail. During it, both Henry and Naomi lost their lives and left their seven children orphaned. Later adopted by Marcus and Narcissa Whitman, missionaries in what is now Washington, they were orphaned a second time, when both their new parents were killed during the Whitman massacre in November 1847.
About 1860 Catherine, the oldest girl, wrote a first-hand account of their journey across the plains and their life with the Whitmans. Today it is regarded as one of the most authentic accounts of the American westward migration.
