Roosevelt’s aggressive enforcement of the Sherman Antitrust Act, which led to the breakup of major trusts like Standard Oil, demonstrates a significant impact on monopolies.

Roosevelt’s emphasis on diplomatic policies abroad diverted attention from domestic issues and minimized the need for aggressive antitrust measures.

Roosevelt’s focus on conservation through the creation of the National Park Service was his primary domestic achievement, sidelining antitrust efforts.

The establishment of regulatory agencies under his administration was more symbolic than effective in regulating large corporations.