What principle was established by the Supreme Court case Marbury v. Madison?

The principle established by the Supreme Court case Marbury v. Madison is judicial review. This landmark decision, made in 1803, empowered the Supreme Court to invalidate laws and actions that are found to be unconstitutional. The case arose when William Marbury petitioned the Supreme Court to compel Secretary of State James Madison to deliver his commission to become a justice of the peace. In its ruling, the Supreme Court, led by Chief Justice John Marshall, declared that it had the authority to review acts of Congress and determine whether they aligned with the Constitution. This established the judiciary's role as a check on the legislative and executive branches, securing the balance of power as envisioned by the framers of the Constitution. Judicial review remains a fundamental aspect of the American legal system, allowing the courts to uphold the rule of law and protect individual rights.