In the United States, judicial review is the legal power of a court to determine if a statute, treaty, or administrative regulation contradicts or violates the provisions of existing law, a State Constitution, or ultimately the United States Constitution. While the U.S. Constitution does not explicitly define the power of judicial review, the authority for judicial review in the United States has been inferred from the structure, provisions, and history of the Constitution. Two landmark decisions by the U.S. Supreme Court served to confirm the inferred constitutional authority for judicial review in the United States. In 1796, Hylton v. United States was the first case decided by the Supreme Court involving a direct challenge to the constitutionality of an act of Congress, the Carriage Act of 1794 which imposed a "carriage tax". The Court performed judicial review of the plaintiff's claim that the carriage tax was unconstitutional. After review, the Supreme Court decided the Carriage Act was constitutional. In 1803, Marbury v. Madison was the first Supreme Court case where the Court asserted its authority to strike down a law as unconstitutional. At the end of his opinion in this decision, Chief Justice John Marshall maintained that the Supreme Court's responsibility to overturn unconstitutional legislation was a necessary consequence of their sworn oath of office to uphold the Constitution as instructed in Article Six of the Constitution. , the United States Supreme Court has held 176 Acts of the U.S. Congress unconstitutional. In the period 1960–2019, the Supreme Court has held 483 laws unconstitutional in whole or in part. Judicial review before the Constitution Before the Constitutional Convention in 1787, the power of judicial review had been exercised in a number of states. In the years from 1776 to 1787, state courts in at least seven of the thirteen states had engaged in judicial review and had invalidated state statutes because they violated the state constitution or other higher law. The first American decision to recognize the principle of judicial review was Bayard v. Singleton, decided in 1787 by the Supreme Court of North Carolina's predecessor. The North Carolina court and its counterparts in other states treated state constitutions as statements of governing law to be interpreted and applied by judges. These courts reasoned that because their state constitution was the fundamental law of the state, they must apply the state constitution rather than an act of the legislature that