The U.S. Supreme Court case Federal Baseball Club of Baltimore, Inc. v. National League of Professional Baseball Clubs et al., 1921, revolved around the issue of whether professional baseball games were subject to federal antitrust laws or not. The Federal Baseball Club sued the National League and other defendants for conspiring to monopolize baseball by buying out competitors and fixing prices for player contracts, which they claimed was a violation of the Sherman Antitrust Act. However, in a unanimous decision led by Justice Oliver Wendell Holmes Jr., the court ruled that organized baseball is not considered interstate commerce as it involves sporting events rather than trade or commerce per se; thus it does not fall under federal jurisdiction according to their interpretation of antitrust laws at that time.

In the case of Federal Baseball Club of Baltimore, Inc. v. National League of Professional Baseball Clubs, there was no dissenting opinion recorded as it was a unanimous decision by the Supreme Court. The court ruled that professional baseball games did not constitute interstate commerce and therefore were not subject to federal antitrust laws. This ruling has since been upheld in subsequent cases despite significant changes in both the business structure and scale of Major League Baseball.