Mormonism and polygamy

Polygamy (called plural marriage by Latter-day Saints in the 19th century or the Principle by modern fundamentalist practitioners of polygamy) was practiced by leaders of the Church of Jesus Christ of Latter-day Saints (LDS Church) for more than half of the 19th century, and practiced publicly from 1852 to 1890 by between 20 and 30 percent of Latter-day Saint families. Polygamy among Latter-day Saints has been controversial, both in Western society and within the LDS Church itself. Many U.S. politicians were strongly opposed to the practice; the Republican platform even referred to polygamy and slavery as "the twin relics of barbarism." Joseph Smith, founder of the Latter-day Saint movement, first introduced polygamy privately in the 1830s. Later, in 1852, Orson Pratt, a member of the Quorum of the Twelve Apostles, publicly announced and defended the practice at the request of then-church president Brigham Young.

Throughout the 19th and early 20th centuries, the LDS Church and the United States remained at odds over the issue. The church defended polygamy as a matter of religious freedom, while the federal government, in line with prevailing public opinion, sought to eradicate it. Polygamy likely played a role in the Utah War of 1857–1858, as Republican critics portrayed Democratic President James Buchanan as weak in opposing both polygamy and slavery. In 1862, the U.S. Congress passed the Morrill Anti-Bigamy Act, prohibiting polygamous marriage in the territories. Despite the law, many Latter-day Saints continued to practice polygamy, believing it was protected by the First Amendment. However, in 1879, the U.S. Supreme Court upheld the Morrill Act's constitutionality in Reynolds v.