This is a list of cases reported in volume 247 of United States Reports, decided by the Supreme Court of the United States in 1918. Justices of the Supreme Court at the time of volume 247 U.S. The Supreme Court is established by Article III, Section 1 of the Constitution of the United States, which says: "The judicial Power of the United States, shall be vested in one supreme Court . . .". The size of the Court is not specified; the Constitution leaves it to Congress to set the number of justices. Under the Judiciary Act of 1789 Congress originally fixed the number of justices at six (one chief justice and five associate justices). Since 1789 Congress has varied the size of the Court from six to seven, nine, ten, and back to nine justices (always including one chief justice). When the cases in volume 247 were decided the Court comprised the following nine members: Notable Case in 247 U.S. Hammer v. Dagenhart In Hammer v. Dagenhart, 247 U.S. 251 (1918), the Supreme Court struck down a federal law regulating child labor. 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. By a 5-4 majority, the Supreme Court struck down the Keating–Owen Act, holding that the Commerce Clause did not give Congress the power to regulate working conditions. In a dissenting opinion, Justice Oliver Wendell Holmes Jr., joined by three other justices, argued that goods manufactured in one state and sold in other states were, by definition, interstate commerce, and so Congress should have power to regulate the manufacturing of those goods. In 1941 Hammer v. Dagenhart was overruled by the Court in United States v. Darby Lumber Co. Citation style Under the Judiciary Act of 1789 the federal court structure at the time comprised District Courts, which had general trial jurisdiction; Circuit Courts, which had mixed trial and appellate (from the US District Courts) jurisdiction; and the United States Supreme Court, which had appellate jurisdiction over the federal District and Circuit courts—and for certain issues over state courts. The Supreme Court also had limited original