In the United States v. Macmillan et al., 1919, the Supreme Court examined whether a federal district court had jurisdiction over an action brought by the United States to cancel land patents issued on account of alleged fraud and mistake. The case involved two mining companies that allegedly obtained several thousand acres of public lands in Alaska through fraudulent means. They were accused of conspiring with government officials to secure these lands under false pretenses, specifically by misrepresenting them as agricultural when they were actually valuable coal lands. The Supreme Court held that while courts generally do not have power to annul or set aside rights conveyed via land patents once delivered and accepted, exceptions exist where fraud or mistakes are involved. In such cases, if it can be shown that there was a gross mistake of fact or law misleading everyone concerned at every step so as to produce serious injustice which would make it unconscionable for the grantor (in this case, U.S Government) not to correct it; then equity will intervene and treat patentee as trustee holding title for benefit of true owner.

The dissenting opinion in the case of United States v. Macmillan et al., 1919, argued that the majority's decision to uphold a conviction for conspiracy to obstruct commerce was incorrect and overreached its authority under the Sherman Act. The dissenters believed that there was insufficient evidence presented at trial to prove an actual obstruction or restraint of trade as required by law. They also disagreed with the interpretation of "intent" used by the majority, arguing it should not be sufficient merely to show intent without demonstrating any concrete action taken towards fulfilling this intention. Furthermore, they expressed concern about potential implications on freedom of speech and assembly rights if mere discussion or agreement could constitute a criminal act under antitrust laws without requiring proof of tangible harm done to competition.