Judicial review empowers the Supreme Court to assess and potentially invalidate laws and executive actions that violate the Constitution. This crucial function allows the Court to check the other branches of government, protect individual rights, and interpret the Constitution's meaning in specific cases. The landmark case Marbury v. Madison (1803) established judicial review in the United States. Chief Justice John Marshall's ruling asserted the Court's power to declare laws unconstitutional, setting a precedent that has become a cornerstone of American constitutional law.