Which Supreme Court case established the principle of judicial review?

The principle of judicial review, which allows the Supreme Court to invalidate laws and executive actions that are contrary to the Constitution, was established in the landmark case of Marbury v. Madison. This case, decided in 1803, marked a foundational moment in American constitutional law. In this case, Chief Justice John Marshall asserted that it is the duty of the judiciary to interpret what the law is and to determine when a law is in conflict with the Constitution.

The ruling set the precedent that the Supreme Court has the authority to review acts of Congress and determine their constitutionality, thereby solidifying the judiciary's role in ensuring that legislation adheres to the Constitution. This created a system of checks and balances among the branches of government, reinforcing the judiciary as an essential arbiter in cases where the legality of legislative and executive actions is questioned.

Other cases mentioned, such as Brown v. Board of Education, Roe v. Wade, and Gideon v. Wainwright, are significant in their own rights, addressing important civil rights issues and the rights of defendants, but they did not establish the principle of judicial review, which is foundational to the operation of the U.S. legal system as interpreted through Marbury v. Madison.