The article examines the activities of James Jesse Strang (1813-1856), the self-proclaimed prophet of the «Latter-day Saints», the leader of one of the major movements in early Mormonism, and his followers – the Strangites. A unique religious and socio-political phenomenon: the proclamation of the monarchy in the United States remains practically unexplored in Russian historiography. This article helps fill the gap. The analysis of information about the religious movement of the Strangites, its origin, features, main ideas, major milestones of history contained in Mormon documents, materials of the American periodical press and other sources of the middle of the XIX-th century is carried out. After the death of the founder of the Mormon religion, Joseph Smith (1805-1844), Strang managed to unite the intra-church opposition around him for a short time. He was supported by almost all dissatisfied with the new leader of The Church of Jesus Christ of Latter-day Saints Brigham Young (1801-1877) and the Quorum of the Twelve Apostles (including many family members of the first Mormon prophet). They managed to create a separate religious organization. It is shown that Strang's ideal was not just a theocracy, but a theocratic monarchy, reminiscent of the theocratic rule of the ancient Jews during the Old Testament period. This radically distinguished his teaching from the ideas about the state structure of other Mormons, who were supporters of theodemocracy – an ideal government based on faith in God and built on the principles of republicanism. The separated Mormons sought to implement their utopian religious-political and social project in practice in the colonized region of the Great Lakes. But conflicts with local residents created great difficulties for the Strangites, acquiring an increasingly acute character in 1850–1856. The conflicts ended with the death of the prophet Strang, the expulsion of his followers from the island settlement, which led to the rapid disintegration of the community. The utopia of the Strangites turned out to be unrealized.