What was the reasoning behind the Supreme Court's decision in Marbury v. Madison? What is the principle of judicial review?

Madison, legal case in which, on February 24, 1803, the U.S. Supreme Court first declared an act of Congress unconstitutional, thus establishing the doctrine of judicial review. The court's opinion, written by Chief Justice John Marshall, is considered one of the foundations of U.S. constitutional law. The U.S. Supreme Court case Marbury v. Madison (1803) established the principle of judicial review—the power of the federal courts to declare legislative and executive acts unconstitutional. The unanimous opinion was written by Chief Justice John Marshall.

Explanation:

to protest slavery i would think it would be a

john maynrd keynes developed new economic respose to the                           ( b. great depression if the 1930's)