Lemon v. Kurtzman clarified the First Amendment by setting a three-pronged test, known as the Lemon Test, to determine if a law violates the Establishment Clause.
This test requires that a law must have a secular purpose, its primary effect must neither advance nor inhibit religion, and it must not result in excessive entanglement between government and religion. If a law fails any of these prongs, it is considered unconstitutional under the Establishment Clause. The Lemon Test has been used by courts to evaluate a wide range of laws and government actions, from school prayer policies to public funding of religious schools or organizations.
