Mormon Fundamentalism refers to a group of religious movements that emerged in the late 19th century among members of the Latter-day Saint movement, particularly after the mainstream church, known as the Church of Jesus Christ of Latter-day Saints, officially abandoned the practice of polygamy. These groups seek to adhere closely to the original teachings and practices of early church leaders, including Joseph Smith and Brigham Young. Fundamentalist Mormons often emphasize the importance of plural marriage, strict adherence to religious texts, and a belief in ongoing revelation. They typically live in isolated communities and maintain distinct cultural practices, setting themselves apart from the mainstream church and its more modern interpretations of faith.