This article examines religion, violence, and westward migration in early national and antebellum America. In treating the Mountain Meadows Massacre of 1857, the authors demonstrate how recognition of religion enriches understanding of the event and its roots in culture and geography. Close attention to and careful interpretation of the lives of the leaders of Methodist migrants (who were killed at Mountain Meadows) and the local Mormon militia (who did the killing) yield vitally connected strands of personal and spiritual history. Placing both men in their religious communities and probing their family strategies reveals how much they had in common. These shared beliefs and practices affected Mormons’and Methodists’ understanding of the meaning of migration, as well as the role and nature of the Kingdom of God in American expansion. The approach taken here takes a panoramic view of the fatal convergence in southern Utah, and integrates religious history with scholarship on empire, slavery, patriarchy, Native dispossession, westward migration, and their reverberations in history. In light of these overlapping beliefs and histories, the massacre is revealed as more intimate, a fratricide among white men who imagined that their religious identities were locked in fatal conflict, but many of whose basic assumptions were shared. This article also engages with the challenges presented by an incomplete archive (all records of the train were lost – likely destroyed by the perpetrators), and the rewards as well as perils of using family histories and survivors’ accounts, as well as more traditional archival materials.