Which Supreme Court case is associated with striking down a federal child labor law and illustrating limits on federal power over interstate commerce?

• A. Plessy v. Ferguson
• B. Lochner v. New York
• C. Hammer v. Dagenhart
• D. United States v. E. C. Knight Co.

Answer: (C)

This question tests how the federal government’s power under the Commerce Clause was limited in the early 20th century. Hammer v. Dagenhart (1918) struck down a federal child labor law, the Keating-Owen Act, because it regulated production in factories, not the interstate shipment of goods. The Court reasoned that production occurs within states and is not commerce, so Congress could not regulate it under the Commerce Clause—even though the products might later move across state lines. This decision emphasizes that, at that time, there were limits to federal authority over interstate commerce and that states retained police power over labor conditions in manufacturing.