Which case established the supremacy of federal law over state law?

• A. McCulloch v. Maryland
• B. Gibbons v. Ogden
• C. United States v. Lopez
• D. United States v. Virginia

Answer: (A)

The main idea tested here is federal supremacy over state law under the Supremacy Clause. In McCulloch v. Maryland, the Supreme Court held that Congress has implied powers to carry out its enumerated functions (like creating a national bank) and that states cannot tax or obstruct federal instruments. This ruling confirms that when federal law and state law conflict, federal law prevails and states cannot undermine federal authority.

Gibbons v. Ogden is related in showing strong federal power to regulate interstate commerce, reinforcing federal authority, but it isn’t the example that establishes the general principle of supremacy. United States v. Lopez set limits on federal power by restricting the reach of the Commerce Clause, illustrating boundaries rather than supremacy itself. United States v. Virginia dealt with equal protection and state action, not the supremacy of federal laws over state laws.