The U.S. Congress passed several laws to help promote competition by outlawing unfair methods of competition:
• The Sherman Act is the nation’s oldest antitrust law. Passed in 1890, it makes it illegal for competitors to make agreements with each other that would limit competition. The Act also makes it illegal for a business to be a monopoly if that company is cheating or not competing fairly.
• The Clayton Act was passed in 1914. The Clayton Act helps protect American consumers by stopping mergers or acquisitions that are likely to stifle competition.
• With the Federal Trade Commission Act (1914), Congress created a new federal agency to watch out for unfair business practices—and gave the Federal Trade Commission the authority to investigate and stop unfair methods of competition and deceptive practices.
Source Federal Trade Commission: https://www.consumer.ftc.gov/sites/default/files/games/off-site/youarehere/pages/pdf/FTC-Competition_Antitrust-Laws.pdf
Today, the Federal Trade Commission’s (FTC’s) Bureau of Competition and the Department of Justice’s Antitrust Division enforce these three core federal antitrust laws. The agencies talk to each other before opening any investigation to decide who will investigate the facts and work on any case that might be brought. Every state has antitrust laws, too; they are enforced by each state’s attorney general.