Final answer:
Judicial review is the power of the courts to overturn laws based on their constitutionality. The Supreme Court first exercised this power in the case of Marbury v. Madison in 1803. It is an important aspect of our legal system.
Step-by-step explanation:
Judicial review is the power of the courts to overturn laws or other actions of Congress and the Executive Branch based on their constitutionality. This principle allows courts to establish quasi-legislation (legislation created from the bench) which often leads to accusations of "judicial activism".
The Supreme Court first exercised this power in the case of Marbury v. Madison in 1803. This landmark case established the concept of judicial review and the Court's authority to declare acts of Congress unconstitutional.
Judicial review is an important aspect of our legal system as it allows the Supreme Court to check the other branches of government and ensure that their actions are in line with the Constitution.