1838 Mormon War

The 1838 Mormon War, also known as the Missouri Mormon War, was a series of armed conflicts between Mormons (Latter Day Saints) and other settlers in northern Missouri during the summer and fall of 1838. Initially characterized by mutual vigilante violence, it escalated into direct intervention by the Missouri state militia. The conflict concluded with the issuance of the Missouri Executive Order 44, which mandated the extermination or the expulsion of the Mormons from the state.

Early Latter Day Saints settled in Missouri driven by religious revelations instructing them to "gather" in Kirtland, Ohio, and Jackson County, Missouri. Facing increasing hostility from neighboring settlers, an 1833 crisis resulted in their forceful eviction from Jackson County by vigilantes. The Missouri legislature created Caldwell County in 1836 as a "compromise" for displaced Mormon settlers; however, the relocation of Mormon leaders from Kirtland in early 1838 intensified fears of Mormon consolidation and expansion in the state.

Violence reignited on August 6, 1838, after a group attempted to prevent Mormons from voting in Gallatin, Daviess County, Missouri, catalyzing the formation of vigilance committees that sought to expel the Mormons from Missouri. Local militia largely failed to quell the unrest, which rapidly escalated into a series of raids and counter-raids. Key engagements included the Battle of Crooked River (October 24), and the Haun's Mill Massacre (October 30) where anti-Mormon vigilantes killed 17 unarmed Latter Day Saints.

After the engagements at Crooked River, Missouri Governor Lilburn Boggs concluded that the Mormons were in open insurrection against state authority, and issued an order on October 27 commanding state troops that they "must be exterminated or driven from the state." Mormons surrendered on November 1, 1838. The state's response to the conflict provoked widespread controversy and severely damaged Boggs's political standing. The war resulted in 22 deaths and the displacement of 10,000 Latter Day Saints, most seeking refuge in the state of Illinois.