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.

When the cases in volume 221 were decided the Court comprised the following nine members: Standard Oil Co. v. United States, 221 U.S. 1 (1911), and United States v. American Tobacco Co., 221 U.S. 106 (1911), are a pair of major antitrust decisions by the Supreme Court.

In Standard Oil the Court found the company guilty of monopolizing the petroleum industry through a series of abusive and anticompetitive actions.

[2][3]) The Court in American Tobacco held the combination in that case was in restraint of trade and an attempt to monopolize the business of tobacco in interstate commerce within the prohibitions of the Sherman Antitrust Act of 1890.