The Sherman Antitrust Act was passed in on June 20, 1890 and was signed into law by President Harrison on July 2, 1890. The law was Congress' first action to prohibit trusts.
The ourdocuments.gov website states, "The Sherman Act authorized the Federal Government to institute proceedings against trusts in order to dissolve them. Any combination “in the form of trust or otherwise that was in restraint of trade or commerce among the several states, or with foreign nations” was declared illegal. Persons forming such combinations were subject to fines of $5,000 and a year in jail. Individuals and companies suffering losses because of trusts were permitted to sue in Federal court for triple damages. The Sherman Act was designed to restore competition but was loosely worded and failed to define such critical terms as “trust,” “combination,” “conspiracy,” and “monopoly.” Five years later, the Supreme Court dismantled the Sherman Act in United States v. E. C. Knight Company (1895). The Court ruled that the American Sugar Refining Company, one of the other defendants in the case, had not violated the law even though the company controlled about 98 percent of all sugar refining in the United States. The Court opinion reasoned that the company’s control of manufacture did not constitute a control of trade."