I consider the government of the United States as interdicted by the Constitution from intermeddling with religious institutions, their doctrines, discipline, or exercises. This results not only from the provision that no law shall be made respecting the establishment or free exercise of religion, but from that also which reserves to the States the powers not delegated to the United States. Certainly, no power to prescribe any religious exercise or to assume authority in any religious discipline has been delegated to the General Government. It must then rest with the States.
Thomas Jefferson (1808)