Sec. of State James Madison held up one of John Adams' "Midnight Judges" appointments. The appointment was for a Justice of the Peace position for William Marbury. Marbury sued. Fellow Hamiltonian and Chief Justice John Marshall dismissed Marbury's suit, avoiding a political showdown and magnifying the power of the Court. This case cleared up controversy over who had final say in interpreting the Constitution: the states did not, the Supreme Court did. This is judicial review.