Answer:
The legislation that played the greatest role in prohibiting the formation and operation of monopolies in the late 1800s the Sherman Anti-Trust Act.
Step-by-step explanation:
The Sherman Anti-Trust Act of July 2, 1890 was the first attempt by the American government to limit anti-competitive behavior by companies: it thus signified the birth of modern competition law.
The bill aimed at countering the actions of Standard Oil, which was constituted as a trust and not in the form of a company whose rights were, at the time, limited. Ironically, when Standard Oil was dismantled, it had already taken the form of a company, and the Sherman Antitrust Act hardly applied to trusts. It is supplemented by the Clayton Antitrust Act of 1914.
This law has served as a model for the drafting of the basic texts of several competition laws around the world.