Hammer v. Dagenhart, 247 U.S. 251 (1918), was a 5–4 Supreme Court decision that struck down the Keating-Owen Child Labor Act, holding that Congress had no power under the Commerce Clause to ban the interstate shipment of goods produced by children. The majority drew a hard line between manufacturing and commerce, treating production as a local matter reserved to the states under the Tenth Amendment. The ruling blocked federal child labor regulation for 23 years before the Court reversed itself in United States v. Darby (1941).
The Law the Case Struck Down
Congress passed the Keating-Owen Child Labor Act in 1916 to attack the widespread use of child workers in factories and mines. The Act banned the interstate shipment of goods from any factory or workshop that employed children under 14. It also barred shipments from facilities where children between 14 and 16 worked more than eight hours a day, more than six days a week, or between 7 p.m. and 6 a.m. A separate provision covered mines and quarries, prohibiting shipment of any product from a mine where children under 16 had worked within the previous 30 days.1The Samuel Gompers Papers. Transcript of Keating-Owen Child Labor Act of 1916
The mechanism was indirect on purpose. Under the prevailing understanding of the Constitution, Congress could not regulate factory conditions directly, so it used its power over interstate commerce as leverage. Cut off the market for goods made by children, and the incentive to hire them would collapse. Reformers wanted a national floor because state laws left many Southern textile mills essentially unregulated.
How the Case Reached the Court
Roland Dagenhart worked at a cotton mill in Charlotte, North Carolina. He sued on behalf of himself and his two minor sons, Reuben and John, challenging the Keating-Owen Act before it took effect. Reuben was under 14 and John was between 14 and 16, so both stood to lose their jobs when the law went into force.2Justia U.S. Supreme Court Center. Hammer v Dagenhart, 247 US 251 (1918)
He filed in the United States District Court for the Western District of North Carolina and sought an injunction against W.C. Hammer, the United States Attorney responsible for enforcing the Act in that district.3Oyez. Hammer v Dagenhart The district court blocked enforcement, and Hammer appealed directly to the Supreme Court. The case was decided on June 3, 1918.
The Constitutional Question
The case forced the Court to decide how far Congress’s commerce power reached. Article I, Section 8 lets Congress regulate commerce “among the several states,” but the Constitution never defines commerce. Did that word cover only trade and transportation, or did it extend to the production activities that fed into trade?
Keating-Owen tested the outer edge. Congress was not regulating shipment itself; it was using a shipping ban to control labor conditions inside factories. The Tenth Amendment sharpened the stakes by reserving to the states all powers not granted to the federal government. If labor regulation fell outside the Commerce Clause, it belonged to the states by default, and Dagenhart argued that conditions inside a North Carolina cotton mill were North Carolina’s business.
The 5–4 Majority Opinion
Justice William R. Day wrote for the majority and anchored the opinion in a single rule: manufacturing is not commerce. Production is a local activity that ends before interstate transportation begins. Because the goods themselves were ordinary and harmless, Congress had no basis to block their shipment simply because it disapproved of how they were made.2Justia U.S. Supreme Court Center. Hammer v Dagenhart, 247 US 251 (1918)
Day distinguished earlier decisions upholding federal bans on shipping lottery tickets, impure food, and other items Congress considered harmful. Those goods, he wrote, were themselves dangerous or immoral. Cotton fabric made by a child was indistinguishable from cotton fabric made by an adult. The problem was the process, not the product, and regulating the process of production was a state function.
The opinion treated the Tenth Amendment as an affirmative limit on federal power. If Congress could dictate who worked in a factory, it could eventually control wages, hours, and working conditions across every industry, transferring to Washington authority the Constitution kept local. The reasoning built on United States v. E.C. Knight Co. (1895), which had held that manufacturing was fundamentally different from commerce and could not be reached under the Sherman Antitrust Act.4Justia U.S. Supreme Court Center. United States v E C Knight Co, 156 US 1 (1895) Under that framework, only activities with a direct connection to interstate commerce fell within federal power; manufacturing, agriculture, and mining were treated as having only an indirect effect.
The result: the Keating-Owen Act was unconstitutional, the injunction stood, and goods produced by children continued to move freely across state lines.3Oyez. Hammer v Dagenhart
Justice Holmes’s Dissent
Justice Oliver Wendell Holmes wrote a dissent that would eventually prove more influential than the majority opinion. His argument was direct: Congress has power to regulate interstate commerce in unqualified terms, and regulating includes prohibiting. If Congress could ban lottery tickets, adulterated food, and deceptively packaged products from crossing state lines, it could ban goods made by children.2Justia U.S. Supreme Court Center. Hammer v Dagenhart, 247 US 251 (1918)
Holmes rejected the line between harmful goods and harmless goods produced under harmful conditions. Whether Congress prohibited an article because the product itself was dangerous or because its production offended public policy, the power was the same. On the Tenth Amendment, he was blunt: it reserves powers not granted to the federal government, but the Commerce Clause is a granted power. Once states send products across state lines, they enter a sphere the Constitution assigned to Congress, and Congress could carry out its view of public policy “whatever indirect effect” that policy might have on activities within the states.2Justia U.S. Supreme Court Center. Hammer v Dagenhart, 247 US 251 (1918)
He also warned that the Court had no business second-guessing Congress’s policy judgment. If a statute fell within an enumerated power, its wisdom belonged to the legislature.
What Congress Tried Next
With Keating-Owen dead, Congress tried a tax. In 1919 it imposed a 10% excise on the net profits of businesses employing children, but the Supreme Court struck that law down in Bailey v. Drexel Furniture Co. (1922), calling it a penalty disguised as a tax.
Congress then proposed a constitutional amendment in 1924 that would have given it explicit power to regulate child labor. Opposition from manufacturers, agricultural interests, and states’ rights advocates stalled ratification. By 1937 only 28 states had ratified, short of the 36 then required. The amendment was never ratified and technically remains pending, though later legislation made it moot.
How United States v. Darby Overruled the Decision
Congress passed the Fair Labor Standards Act in 1938, establishing minimum wages, maximum hours, and child labor restrictions for workers producing goods destined for interstate commerce. The statute rested on the same Commerce Clause theory the Court had rejected in 1918.
In United States v. Darby, 312 U.S. 100 (1941), the Supreme Court upheld the Fair Labor Standards Act unanimously and overruled Hammer v. Dagenhart by name. The Court said the reasoning in Hammer “was a departure from the principles which have prevailed in the interpretation of the Commerce Clause both before and since the decision” and that whatever precedential force it once had “has long since been exhausted.”5Justia U.S. Supreme Court Center. United States v Darby, 312 US 100 (1941)
Darby rejected the manufacturing-versus-commerce distinction that had been the cornerstone of Day’s opinion. Manufacturing is not itself interstate commerce, the Court acknowledged, but shipping manufactured goods across state lines is, and Congress can regulate the conditions of production when those goods are bound for interstate markets. The Court also dismantled the Tenth Amendment argument, holding that the amendment “is but a truism” that adds nothing the Constitution does not already say and does not strip Congress of powers otherwise granted.5Justia U.S. Supreme Court Center. United States v Darby, 312 US 100 (1941) The reasoning tracked Holmes’s dissent almost exactly.
Why the Case Still Matters
Hammer v. Dagenhart marks the high point of a constitutional theory that no longer controls. Its core holding was abandoned in Darby, and the manufacturing-versus-commerce distinction borrowed from E.C. Knight has not been revived. Modern Commerce Clause doctrine gives Congress broad authority to regulate economic activities that substantially affect interstate commerce, a standard that would easily sustain the Keating-Owen Act today.
The case is studied now for what its rise and fall show about constitutional interpretation. For 23 years, it blocked federal child labor regulation and forced reformers into a series of unsuccessful workarounds. Holmes’s dissent, meanwhile, became a canonical example of how a minority opinion can reshape the law: his view that the commerce power includes the power to prohibit, and that the Tenth Amendment does not subtract from enumerated federal powers, is the accepted framework today.