 The "Free Exercise Clause" states that Congress cannot "prohibit the free exercise" of religious practices.The Supreme Court of the United States has consistently held, however, that the right to free exercise of religion is not absolute.For example, in the 19th century, some of the members of The Church of Jesus Christ of Latter-day Saints traditionally practiced polygamy, yet in "Reynolds v. United States" (1879), the Supreme Court upheld the criminal conviction of one of these members under a federal law banning polygamy.