During the Progressive Era, public sentiment in the United States turned against what was perceived as increasingly intolerable child labor conditions. In response, Congress passed the Keating–Owen Act, prohibiting the sale in interstate commerce of any merchandise that had been made either by children under the age of fourteen, or by children under sixteen who worked more than sixty hours per week. In his majority opinion, Justice William R. Day struck down the Keating–Owen Act, holding that the Commerce Clause did not give Congress the power to regulate working conditions. In his dissenting opinion, Justice Oliver Wendell Holmes Jr. argued that goods manufactured in one state and sold in other states were, by definition, interstate commerce, and thus Congress should have power to regulate the manufacturing of those goods.