Which act was intended to stop illegal activity? What activity was it supposed to stop?

The Sherman Antitrust Act (Sherman Act, 26 Stat. 209, 15 U. S. C. §§ 1-7) is a landmark federal statute in the history of United States antitrust law (or " competition law ") passed by Congress in 1890. Passed under the presidency of Benjamin Harrison, it prohibits certain business activities that federal government regulators deem to be anti-competitive, and requires the federal government to investigate and pursue trusts.