Two landmark decisions of the United States 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 that involved a direct challenge to the constitutionality of an act of Congress, the Transportation Act of 1794 that imposed a "transportation tax." [2] The Court engaged in the judicial review process by examining the plaintiff's claim that the transportation tax was unconstitutional . After review, the Supreme Court decided that the Transportation Law was constitutional. In 1803, Marbury v. Madison [3] was the first Supreme Court case where the Court affirmed its authority for judicial review to nullify a statute as unconstitutional. At the end of his opinion on this decision, [4] Chief Justice John Marshall held that the Supreme Court's responsibility to overturn unconstitutional legislation was a necessary consequence of his oath of office to uphold the Constitution as indicated in Article Six of the Constitution.
