Which case established that the federal government has implied powers under the Necessary and Proper Clause and that federal law is supreme over state law?

• A. United States v. Lopez
• B. Plessy v. Ferguson
• C. McCulloch v. Maryland
• D. Marbury v. Madison

Answer: (C)

This question tests how the Constitution allows the federal government to act beyond its enumerated powers and how federal law defeats state laws when they clash.

McCulloch v. Maryland (the Bank of the United States case) is the landmark decision. The Court said Congress can use powers not explicitly listed in the Constitution if doing so is a reasonable means to execute its enumerated powers, via the Necessary and Proper Clause. Creating a national bank was viewed as a legitimate way to manage the finances of the United States—borrowing, collecting taxes, regulating currency—even though a bank isn’t named in the Constitution. At the same time, the Court affirmed the Supremacy Clause: states cannot tax or interfere with federal instruments, so Maryland’s attempt to tax the national bank was unconstitutional. This combination establishes two key ideas: Congress has implied powers to carry out its duties, and federal law is the supreme law of the land.

Other cases differ: United States v. Lopez limits Congress’s reach under the Commerce Clause, Plessy v. Ferguson concerns segregation and equal protection, and Marbury v. Madison concerns judicial review. None of these establish the specific idea that the federal government has implied powers under the Necessary and Proper Clause and that federal law is supreme over state law.