Why was Roosevelt considered a trust buster?

 Theodore Roosevelt, the 26th President of the United States, who served from 1901 to 1909, earned the nickname "trust buster" because of his rigorous enforcement of antitrust laws, and his administration's efforts to break up large monopolistic corporations, known as "trusts," which he believed wielded too much power over the economy. Roosevelt did not oppose all trusts, but he distinguished between those he saw as benefiting the public and those that were harmful.

One of the key factors that made Roosevelt a trust buster was his use of the Sherman Antitrust Act of 1890. While this law had been relatively ineffective before his presidency, Roosevelt employed it to regulate big businesses. One of the major cases that underscored his dedication to busting trusts was the successful lawsuit against J.P. Morgan's Northern Securities Company in 1902, which was a large railroad trust. This effort initiated a series of cases against large corporations in an attempt to protect trade and commerce against unlawful restraint and monopoly.

Through these actions, Roosevelt showed that the federal government intended to enforce federal laws against monopolies and signaled an important change in the relationship between the government and big business.