The case of Hammer v. Dagenhart et al. dealt with the constitutionality of the Act of September 1, 1916, which prohibited the transportation of goods made in factories where children under 14 years of age were employed or where children between 14 and 16 years of age were employed for more than eight hours a day, more than six days a week, or outside of certain hours. The Supreme Court found the act unconstitutional as it exceeded the commerce power of Congress and invaded the powers reserved to the States. The power to regulate interstate commerce only allows for the control of the means by which it is carried out, not the exclusion of goods unless they pose a unique threat to the State or Nation. The court has never upheld the right to exclude goods unless it is necessary to prevent inherent evils. The production of goods is not considered commerce and is not subject to Congress' control, even if they are intended for interstate commerce. The power to regulate interstate commerce does not allow Congress to equalize economic conditions or prevent unfair competition by prohibiting the transportation of goods made under certain conditions. This power also does not allow Congress to control the States' police power over local trade and manufacture, which is reserved to them by the Tenth Amendment. The decision was affirmed by the Supreme Court.

The statute in question prohibits manufacturers who employ children within prohibited ages from using interstate commerce facilities, but the goods shipped are harmless. The production of goods intended for interstate commerce is not subject to federal control under the commerce power. Congress cannot regulate the shipment of goods made by children in interstate commerce to prevent unfair competition. The Commerce Clause was not intended to give Congress the authority to equalize economic conditions between states. States have the power to regulate internal commerce, including inspection, quarantine, health, turnpike-roads, and ferries. The Constitution does not intend to restrict states in regulating their internal civil institutions, but there should be limitations on employing children in mines and factories for their own and public welfare.

The power of the States to regulate their purely internal affairs is inherent and has never been surrendered to the federal government. The act in question prohibits the movement of ordinary commercial commodities in interstate commerce to regulate the hours of labor of children in factories and mines within the States, which is a purely state authority. The law in question exceeds Congress's constitutional authority, and the District Court's decision must be affirmed. However, the statute being challenged falls within Congress's power to regulate interstate and foreign commerce, including the power to prohibit certain goods from being transported. The act is constitutional, and any challenge to its validity must be based on a collateral ground. The author argues that Congress should be allowed to exercise its powers to address the issue of child labor, which falls under the jurisdiction of Congress.