Which U.S. Supreme Court case established that employers may not use child labor in interstate commerce under the Fair Labor Standards Act?

United States v. Darby Lumber Co. upheld the federal government’s power to regulate labor conditions connected with interstate commerce under the Fair Labor Standards Act.

The Supreme Court decided the case in 1941. Darby Lumber had challenged federal minimum-wage and maximum-hours requirements, as well as restrictions on shipping goods produced under substandard labor conditions.

The Court unanimously upheld the statute and rejected the reasoning of Hammer v. Dagenhart, an earlier 1918 decision that had limited federal child-labor regulation. Darby became an important Commerce Clause precedent.

The case did not create every child-labor rule by itself. Rather, it confirmed Congress’s authority to regulate production and employment practices when they substantially relate to interstate commerce.