Supreme Court Rules Unincorporated Unions Can Be Sued in Coronado Coal Case

The Supreme Court rules in United Mine Workers v. Coronado Coal Co. that unincorporated labor unions can be sued in federal court as legal entities, establishing a precedent that exposes unions to potentially devastating civil liability. The case arises from Arkansas’s Sebastian County Union War of 1914, during which violence occurred at Coronado Coal Company facilities during a strike. While the Court vacates a lower court judgment finding the union violated the Sherman Antitrust Act—reasoning that coal mining itself is not interstate commerce and the company failed to prove the union intended to restrain interstate trade—the decision opens unions to lawsuits in ways corporations had long feared for themselves.

Chief Justice William Howard Taft’s opinion establishes that unincorporated associations like unions can be treated as legal entities capable of being sued, despite lacking formal corporate structure. This seemingly technical legal ruling has profound implications for the labor movement: unions now face potential financial destruction through civil judgments, while the evidentiary bar for proving antitrust violations remains ambiguous. The decision requires proof that unions specifically intended to restrain interstate commerce, but leaves unclear what evidence suffices to demonstrate such intent.

The temporary victory for the United Mine Workers proves hollow, as the Coronado Coal Company immediately begins gathering evidence of intent to restrict trade in non-union coal. This leads to a second Supreme Court case in 1925 that reverses the union’s fortunes entirely. The 1922 decision’s establishment of union suability becomes a weapon wielded against organized labor throughout the 1920s, as employers file numerous antitrust suits seeking massive damages and injunctions against strikes. The ruling demonstrates how ostensibly neutral legal doctrines—unions and corporations both being suable entities—operate asymmetrically in practice, with corporations using litigation to drain union treasuries and deter organizing while bearing minimal antitrust risk themselves.