The definition of religious freedom from the Virginia Statute for Religious Freedom (1786) to the most recent U.S. Supreme Court decision is not clear and well-defined. The two religious clauses found in the First Amendment to the U.S. Constitution (those denying Congress the right either to establish religion or to prohibit its free exercise) applied only to the federal government for the first 100 years of U.S. history. Early court cases included Barron v. Baltimore and Permoli v. First Municipality of New Orleans. Court related issues included religious tests for public office, tax exempt status for property used for religious purposes, and enforced laws against blasphemy. Social issues involved opposition to Catholics, Jews, and atheists, and a general lack of religious tolerance. Following the Civil War, new problems arose concerning religious freedom. The U.S. Supreme Court ruled in favor of a belief/action dichotomy and established the incorporation doctrine, whereby it was determined that the rights guaranteed in the first eight amendments limited the actions of states as well as of the federal government. A number of cases testing either the "establishment" clause or the "free exercise" clause are described. Cases such as McCullum v. Board of Education and Wisconsin v. Yoder pointed out the difficulty in delineating the proper line of neutrality in the establishment clause cases, while the case of Wisconsin v. Yoder, in which Amish beliefs came into conflict with state law, represented a landmark victory for the idea of "free exercise." An appendix contains excerpts from 23 documents including: The Virginia Statute for Religious Freedom; John F. Kennedy on Church and State; and 13 Supreme Court decisions on religion clause cases. (DMS)