Answer: anti-trust cases during Teddy Roosevelt's presidency.
Step-by-step explanation:
These particular companies formed monopolies. The government sued these companies, and the Supreme Court ruled that they had violated the Sherman Anti-Trust Act, which required the federal government to investigate and monitor monopolies. While Teddy Roosevelt was president, he implemented many reforms and expanded regulations on businesses. Because of his role in breaking up numerous monopolies, Roosevelt became known as a trust-buster.