The First Amendment of the U.S. Constitution prohibits the government from establishing religion (the Establishment Clause), which the U.S. Supreme Court has interpreted to include a prohibition on official support or endorsement of religion. It also prohibits the government from interfering with individuals' exercise of religion (the Free Exercise Clause). The balancing of these constitutional provisions often leads to questions regarding the extent to which religious activities may occur at public events or within public institutions. On one hand, it may be argued that permitting prayer as a part of publicly sponsored events or activities suggests official support for religion. On the other hand, restricting religious expressions at events or activities may appear to interfere with individuals' ability to exercise their religious beliefs. Lower courts have considered the constitutionality of publicly sponsored prayers in other contexts, including the military chaplaincy as well as invocations and other religious commemorations at public events. School Prayer

As a general rule, publicly sponsored prayer is prohibited by the Establishment Clause. Legal challenges to public prayers have arisen most frequently in the context of school prayers, and the U.S. Supreme Court consistently has struck down school policies that implement official acts of prayer in school settings. The Court noted that the school decided whether to have a prayer at the graduation; which religious participant would deliver the prayer; and what the guidelines for the content of the prayer would be. Constitutional Protections for Individual Religious Activity

Those who disagree with the Court's decisions limiting school prayer have argued that restricting religious activities in schools carries its own risk of violating the First Amendment. The Supreme Court issued its only decision on legislative prayer since Marsh in 2014, clarifying whether legislatures must limit the content of prayers by outside speakers. Standing To Challenge Legislative Prayers

Although the constitutionality of legislative prayers generally has been upheld, legal challenges to such prayers may be difficult to sustain due to restrictions on standing.
The First Amendment of the U.S. Constitution prohibits the government from providing official support or endorsement of religion and from interfering with individuals' exercise of religion. Balancing the constitutional protections under the Establishment and Free Exercise Clauses, as these provisions are known, often leads to questions regarding the extent to which religious activities may occur within public institutions or at public events. On one hand, permitting prayer at publicly sponsored activities arguably may suggest official support for religion. On the other hand, restricting religious expression by individuals at such activities may appear to interfere with their ability to exercise their religious beliefs freely.
As a general rule, publicly sponsored prayer is prohibited under the First Amendment with few exceptions. Legal challenges to prayer in public fora have arisen most frequently in the context of prayer in schools. The U.S. Supreme Court generally has struck down school prayer policies adopted by public schools, even if the content of the prayer is neutral and participation among students is voluntary. This prohibition has been extended to extracurricular and other school-related activities as well, but does not apply to all religious activity in public schools. Rather, the First Amendment prohibits any school-sponsored religious activity, but protects students' ability to pray voluntarily at their own initiative.
Although official prayers by public institutions are generally unconstitutional, there are a few notable exceptions. The Supreme Court has recognized that legislative prayer—invocations made to open legislative sessions—are generally permissible because of the role such prayers have played in the history and tradition of American government. Although the Court acknowledged the constitutionality of legislative prayer, for decades, lower courts generally have had to interpret the parameters of the exemption, including how speakers may be selected and what the content of such prayers may be. The Court issued a decision in Town of Greece, New York v. Galloway in 2014 clarifying that legislative prayers need not be nonsectarian to pass constitutional muster. Furthermore, courts have acknowledged other exemptions, upholding the constitutionality of the military chaplaincy and the use of religious references in official proceedings and on coins and currency.