What did the Supreme Court case Marbury v. Madison establish?

The Supreme Court case Marbury v. Madison, decided in 1803, established the principle of judicial review, which allows the Court to invalidate laws and executive actions that it finds to be in conflict with the Constitution. This landmark decision was pivotal in defining the role of the judiciary within the American system of government.

In this case, William Marbury had been appointed as a justice of the peace but did not receive his commission. He petitioned the Supreme Court to compel Secretary of State James Madison to deliver the commission. Chief Justice John Marshall ruled that while Marbury was entitled to his commission, the section of the Judiciary Act of 1789 that gave the Supreme Court the power to issue such orders was unconstitutional. This ruling established the concept that the Supreme Court could review and nullify actions that contradicted the Constitution, thereby asserting its role as a co-equal branch of government and providing a crucial check on the powers of Congress and the President.

Understanding this principle is fundamental to grasping how judicial authority functions within the framework of American government, as it ensures that no law or executive action can go against the nation's founding document, the Constitution.