Final answer:
President Roosevelt expanded the federal government's role in controlling monopolies by using the Sherman Antitrust Act to break up harmful monopolies and creating the Department of Commerce and Labor to regulate corporate practices.
Step-by-step explanation:
President Theodore Roosevelt expanded the role of the federal government in business monopolies by utilizing the Sherman Antitrust Act to break up monopolies he felt were harmful to the United States. In 1902, he directed the Justice Department to sue the Northern Securities Company, a leading railroad trust, resulting in the Supreme Court dissolving the company by 1904.
Roosevelt's administration initiated 44 antitrust suits, thus securing his reputation as a trustbuster. However, his real intent was to enforce federal regulation of businesses. To counter the dominance of monopolies, Roosevelt also established the Department of Commerce and Labor in 1903, which included the Bureau of Corporations to investigate business practices.
Roosevelt further strengthened the federal government's regulatory powers over the railroads with the passage of the Elkins Act in 1903, which empowered the government to enforce laws against railroad monopolies more effectively. His approach to trust busting set a precedent for the future of federal involvement in curbing the powers of large corporations and ensuring fair competition in the market.