Marbury v. Madison, legal case in which, on February 24, 1803, the U.S. Supreme Court first declared an act of Congress unconstitutional, thus establishing the doctrine of judicial review. The court’s opinion, written by Chief Justice John Marshall, is considered one of the foundations of U.S. constitutional law.
The issue directly presented by Marbury v. Madison can only be described as minor. By the time the court heard the case, the wisdom of Jefferson’s desire to reduce the number of justices of the peace had been confirmed (and the Judiciary Act of 1801 had been repealed) Marbury’s original term was almost half over; and most people, Federalists and Republicans alike, considered the case to be moot. But Marshall, despite the political difficulties involved, recognized that he had a perfect case with which to expound a basic principle, judicial review, which would secure the Supreme Court’s primary role in constitutional interpretation.
Decision:
The chief justice recognized the dilemma that the case posed to the court. If the court issued the writ of mandamus, Jefferson could simply ignore it, because the court had no power to enforce it.