Which act was a significant response to the monopolistic practices of corporations in the late 19th century?

The Sherman Antitrust Act was a significant response to the monopolistic practices of corporations in the late 19th century because it was the first federal legislation aimed specifically at curbing monopolies and promoting competition. Enacted in 1890, the Act made it illegal for companies to restrain trade or commerce through monopolistic practices, essentially laying the groundwork for antitrust laws in the United States.

Its passage stemmed from growing public concern over the power of large corporations and trusts, which were seen as undermining economic fairness and harming consumers and smaller businesses. The Act enabled the federal government to prosecute companies for anti-competitive behaviors and was crucial in the fight against monopolies such as Standard Oil and Pacific Railway.

In contrast, the other options stem from different contexts and purposes. The Federal Trade Commission Act was established later to prevent unfair business practices, the Clayton Act expanded on the Sherman Act by addressing specific anti-competitive practices but was not the initial response, and the McKinley Tariff Act primarily dealt with trade and tariffs rather than corporate monopolies directly. Thus, the Sherman Antitrust Act represents the earliest and most significant legislative attempt to tackle monopolistic corporate power during that era.