What trusts did Theodore Roosevelt target?

Theodore Roosevelt targeted several large corporations and monopolies known as trusts, particularly in the railroad, oil, and beef industries. Notably, he took action against the Northern Securities Company, a railroad trust, and the Standard Oil Company, led by John D. Rockefeller. Roosevelt's administration sought to regulate these trusts to promote fair competition and protect consumers, marking a significant shift in federal policy toward antitrust enforcement. His efforts laid the groundwork for future antitrust legislation.