List of United States Supreme Court cases, volume 310

This is a list of cases reported in volume 310 of United States Reports, decided by the Supreme Court of the United States in 1940.

Justices of the Supreme Court at the time of volume 310 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 310 were decided the Court comprised the following members:

Thornhill v. Alabama
Thornhill v. Alabama, 310 U.S. 88 (1940), is a US labor law case. In it the Supreme Court reversed the conviction of the president of a local union for violating an Alabama statute that prohibited only labor picketing. Thornhill was peaceably picketing his employer during an authorized strike when he was arrested and charged. In reaching its decision, the Supreme Court decided that the free speech clause protects speech about the facts and circumstances of a labor dispute. The statute in the case prohibited all labor picketing, but the Thornhill decision added peaceful labor picketing to the area protected by free speech.

United States v. Socony-Vacuum Oil Company
United States v. Socony-Vacuum Oil Company, 310 U.S. 150 (1940), is a landmark anti-trust decision of the Supreme Court widely cited for the proposition that price-fixing is illegal per se. Socony has been cited and quoted many times for its statements that the rule against price-fixing is sweeping, and was, at least until recently, the most widely cited case on price fixing.

Cantwell v. Connecticut
In Cantwell v. Connecticut, 310 U.S. 296 (1940), the Supreme Court held that the First Amendment's federal protection of religious free exercise incorporates via the Due Process Clause of the Fourteenth Amendment and so applies to state governments too.

Minersville School District v. Gobitis
Minersville School District v. Gobitis, 310 U.S. 586 (1940), involved the religious rights of public school students under the First Amendment to the United States Constitution. The Supreme Court ruled that public schools could compel students (in this case, Jehovah's Witnesses) to salute the American flag and recite the Pledge of Allegiance despite the students' religious objections to these practices. This decision led to increased persecution of Witnesses in the United States. The Supreme Court overruled this decision three years later in West Virginia State Board of Education v. Barnette(1943).

Federal court system
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 jurisdiction (i.e., in which cases could be filed directly with the Supreme Court without first having been heard by a lower federal or state court). There were one or more federal District Courts and/or Circuit Courts in each state, territory, or other geographical region.

The Judiciary Act of 1891 created the United States Courts of Appeals and reassigned the jurisdiction of most routine appeals from the district and circuit courts to these appellate courts. The Act created nine new courts that were originally known as the "United States Circuit Courts of Appeals." The new courts had jurisdiction over most appeals of lower court decisions. The Supreme Court could review either legal issues that a court of appeals certified or decisions of court of appeals by writ of certiorari. On January 1, 1912, the effective date of the Judicial Code of 1911, the old Circuit Courts were abolished, with their remaining trial court jurisdiction transferred to the U.S. District Courts.

List of cases in volume 310 U.S.

 * [a] Hughes took no part in the case
 * [b] Murphy took no part in the case
 * [c] McReynolds took no part in the case
 * [d] Douglas took no part in the case