In 1833, enraged vigilantes expelled 1,200 Mormons from Jackson County, Missouri, setting a precedent for a later expulsion of Mormons from the state, changing the course of Mormon history, and enacting in microcosm a battle over the ultimate source of authority in America’s early democratic society. The purpose of this study is two-fold: first, to reexamine the motives that induced Missourians to expel Mormons from Jackson County in 1833; and second, to explore how government authorities responded to that conflict. Past studies of the Mormon expulsion from Jackson County have argued that Mormon communalism collided with the Jacksonian individualism of Missouri residents, causing hostility and violence. However, in recent years, studies have questioned many of the conventional notions of law and governance in the antebellum era, in particular the argument that Jacksonian society was dominated by an individualistic, egalitarian, laissez-faire creed. Although Jacksonian America was a society in transition, communities continued to emphasize a tradition of localized self government, communal regulation, and distrust of outside interference. Therefore, this study explored how the local orientation of law, regulation, and government in antebellum Missouri contributed to the setting of violence and to the ways local, state, and federal authorities responded to the Mormon expulsion. An analysis of the Jackson County conflict through the lens of American localism reveals the extent to which Mormonism challenged customary notions of local sovereignty, authority, and control.