Marbury v. Madison was a landmark decision of the U.S. Supreme Court that established the principle of judicial review, meaning that American courts have the power to strike down laws and statutes they find to violate the Constitution of the United States. Decided in 1803, Marbury is regarded as the single most important decision in American constitutional law.
In an opinion written by John Marshall, The Supreme Court held that Madison’s refusal to deliver Marbury’s commission was illegal. The Court also held that it was normally proper in such situations for a court to order the government official in question to deliver the commission. In Marbury’s case, however, the Court did not order Madison to comply. Examining the law Congress had passed to define Supreme Court jurisdiction over types of cases like Marbury’s—Section 13 of the Judiciary Act of 1789—the Court found that the Act had expanded the definition of the Supreme Court’s jurisdiction beyond what was originally set forth in the U.S. Constitution. The Court then struck down Section 13 of the Act, announcing that American courts have the power to invalidate laws that they find to violate the Constitution—a power now known as judicial review.