Congress has no power under the Commerce Clause to regulate labor conditions. (Overruled by United States v. Darby Lumber Co. (1941)) Decided June 3, 1918 (argued 1918). Opinion of the Court: William R. Day → go there Dissenting: Holmes. Overruled by United States v. Darby Lumber Co., → go there Topic: Federalism. Hammer v. Dagenhart, 247 U.S. 251 (1918), was a United States Supreme Court decision in which the Court struck down a federal law regulating child labor. The decision was overruled by United States v. Darby Lumber Co. (1941). Wiki link