type: timeline_event On March 14, 1904, the U.S. Supreme Court ruled 5-4 that the Northern Securities Company violated the Sherman Antitrust Act and ordered the railroad holding company dissolved. The decision affirmed the April 9, 1903 federal circuit court ruling against the company formed by J.P. Morgan, James J. Hill, and Edward H. Harriman to control major western railroads. This was the first major antitrust victory in U.S. history and the first Supreme Court decision to uphold enforcement of the Sherman Antitrust Act against corporate interests rather than labor unions. The ruling validated President Theodore Roosevelt's aggressive trust-busting approach and established crucial precedent that even the most powerful financial combinations were subject to federal antitrust law. The case demonstrated that the federal government possessed authority to regulate and dissolve monopolistic corporations that restrained interstate commerce. For Roosevelt, the victory was political and symbolic as much as legal—it proved that a president could challenge Wall Street's most powerful interests and win, fundamentally redefining the relationship between government and corporate power. The Northern Securities precedent would be used by Roosevelt's attorneys general in subsequent suits against Standard Oil, American Tobacco, and Du Pont. However, the decision's 5-4 margin and the dissents revealed ongoing controversy about the scope of federal regulatory power. The case represented the high-water mark of Progressive Era antitrust enforcement, establishing a standard of aggressive trust-busting that would be systematically eroded over the following decades as corporate interests captured regulatory agencies and reshaped antitrust doctrine.