Marbury v. Madison established the Supreme Court's power of judicial review. John Adams appointed William Marbury as a judge on his last day in office, but the appointment was not delivered before Thomas Jefferson took office as the new president. Jefferson refused to deliver the appointment. The Supreme Court, led by Chief Justice John Marshall, ruled that while Marbury was entitled to his appointment, the court did not have constitutional authority to force Jefferson to deliver it. This established the Supreme Court's ability to declare acts of Congress unconstitutional.