The U.S. Supreme Court case Marbury v. Madison (1803) established the principle of judicial review, which is the power of the federal courts to declare legislative and executive acts unconstitutional. The unanimous opinion was written by Chief Justice John Marshall. In this case, William Marbury sued the new secretary of state, James Madison, in order to obtain his commission as justice of the peace, which was withheld by the new administration. The Supreme Court issued its opinion on February 24, 1803, and established the principle of judicial review, which has been an important addition to the system of checks and balances created to prevent any one branch of the Federal Government from becoming too powerful.