In the 1965 case of Western Pacific Railroad Co. et al. v. United States et al., the Supreme Court ruled on a dispute between several railroad companies and the federal government regarding freight rates for transporting certain commodities, specifically petroleum products. The railroads argued that they should be allowed to set their own rates without interference from regulatory agencies such as the Interstate Commerce Commission (ICC). However, these agencies contended that they had authority under existing laws to regulate these rates in order to prevent discriminatory or unfair pricing practices by transportation companies. The Supreme Court sided with the ICC and other regulatory bodies, affirming their right to oversee and control freight rate-setting processes within reasonable bounds established by law. This decision reinforced principles of administrative law concerning agency powers while also emphasizing public interest considerations in economic regulation policy-making.

In the dissenting opinion for Western Pacific Railroad Co. et al. v. United States et al., Justice Harlan disagreed with the majority's interpretation of Section 15(6) of the Interstate Commerce Act, which he believed was intended to provide a broad grant of power to rail carriers to establish joint rates without approval from the Commission in every instance. He argued that this provision should be read as allowing railroads considerable latitude in setting their own rates unless there is evidence that these rates are unjust or unreasonable or otherwise violate antitrust laws, and not as requiring prior approval from the Commission for all such rate agreements between carriers. Furthermore, he contended that this interpretation would better align with Congress' intent when it enacted Section 15(6), which was primarily aimed at preventing discriminatory practices rather than micromanaging railroad pricing decisions.