In the early 1900s, the US government, under President Theodore Roosevelt, went after the “Beef Trust” because it felt that the firms in the trust were conspiring to fix the prices that they would pay to their suppliers and transporters and the prices that would be charged for their products. By banding together, they had enough market share to force both suppliers and consumers to accept the prices set by the trust.
Theodore Roosevelt and other Progressive reformers felt that too many big businesses had monopoly power and that those big businesses tended to use that power to hurt society. They felt that the trusts unfairly avoided competition with one another that would have driven the prices paid to suppliers up and the prices charged to consumers down. They believed that this meant that the trusts were hurting society. In order to prevent this harm, they attacked many trusts. In the 1905 Supreme Court case of Swift v. United States, the Court ruled that the government was justified in attacking the Beef Trust.