What was the significance of Marbury v. Madison?
Marbury v. Madison was significant because with its decision in the case, the Supreme Court established the principle of judicial review. The case stemmed from newly-elected President Thomas Jefferson's refusal to allow his Secretary of State James Madison to deliver commissions for a number of lower-level judicial appointments made by outgoing President John Adams. One of the appointees, William Marbury, challenged Jefferson, claiming that the Judiciary Act empowered (required, even) the Supreme Court to issue a legal writ called a mandamus that would force the President and his Secretary to deliver up the commissions. The Supreme Court, headed by Jefferson's political adversary John Marshall, ruled that this part of the Judiciary Act was in fact unconstitutional. The case was very complex, and not in and of itself all that consequential, but the precedent established by Marshall--that the Court might rule a law passed by Congress unconstitutional--was a very significant one. Though the Court would not exercise judicial review for several decades, the principle of judicial review would over time become a pillar of the system of checks and balances in the U.S. Constitution. It was also one of several landmark decisions issued by the Court under Marshall, whose vision of a robust federal government would prove very influential.