In the 1939 case Union Stock Yard & Transit Co. v. United States, the Supreme Court ruled that a stockyard company was indeed subject to regulation by the Interstate Commerce Commission (ICC). The Union Stock Yard and Transit Company of Chicago argued it merely provided services related to livestock sales and thus should not be considered part of interstate commerce or under ICC jurisdiction. However, the court disagreed, stating that because these activities were so closely tied with interstate commerce - as they involved buying and selling animals transported across state lines for slaughter - they could be regulated under federal law. This decision expanded federal power over business operations associated with interstate trade.

In the dissenting opinion for Union Stock Yard & Transit Co. v. United States, it was argued that the majority's decision to uphold federal regulation of stockyard companies as common carriers under the Interstate Commerce Act extended beyond constitutional boundaries and misinterpreted legislative intent. The dissent contended that stockyards were not directly involved in interstate commerce but merely provided a service incidental to it, thus falling outside of regulatory purview. They also pointed out that Congress did not intend for such businesses to be regulated as common carriers when drafting legislation because they do not transport goods or commodities themselves but rather facilitate transactions between buyers and sellers. Therefore, treating them as such would distort their role within the industry and potentially disrupt market dynamics by imposing undue burdens on their operations.