What significant power was established by the Supreme Court in Marbury v. Madison?

The Supreme Court established the principle of judicial review in the case of Marbury v. Madison in 1803. This case was monumental because it articulated the power of the judiciary to review acts of Congress and determine whether they are consistent with the Constitution. This means that the Supreme Court can invalidate laws that it finds unconstitutional, thereby reinforcing the role of the judiciary as a check on the legislative and executive branches of government. The decision by Chief Justice John Marshall affirmed that the Constitution is the supreme law of the land, and it established the judiciary as a co-equal branch of government capable of reviewing the actions of the other branches to preserve the balance of power.

Other options such as equal protection under the law, freedom of speech, and habeas corpus pertain to different legal principles and cases. Equal protection is primarily established by the Fourteenth Amendment, while freedom of speech is protected under the First Amendment. Habeas corpus refers to the right to seek relief from unlawful detention, which is addressed through different legal frameworks. None of these concepts are directly related to the groundbreaking decision made in Marbury v. Madison.