Hartford Fire Insurance Co. (Hartford) (defendant) was charged by California (plaintiff) with violating the Sherman Act’s antitrust provisions by agreeing to restrict the terms of coverage of commercial general liability insurance available in the United States. Hartford was a London, England insurer, and its conduct occurred only in the United Kingdom. In its defense, Hartford argued that it was unreasonable for U.S. antitrust laws to regulate its conduct. The district court noted that it had jurisdiction over California’s Sherman Act claims against Hartford, and held Hartford liable for antitrust violations. Hartford appealed, arguing that the district court should have declined to exercise its jurisdiction over the case due to principles of international comity. The court of appeals accepted Hartford’s argument that when a conflict between international and domestic laws exists, American courts should respect principles of international comity and decline to exercise jurisdiction unless other factors weigh in favor of exercising jurisdiction. It found that such factors were present in Hartford’s case, including Hartford’s express purpose to affect United States commerce and the substantial nature of the effect produced. The court of appeals held that these factors outweighed the potential conflict between domestic and international laws and supported the court’s exercise of jurisdiction over the litigation. Hartford appealed to the United States Supreme Court.