In the 1932 case of St. Louis Southwestern Railway Co. v. Missouri Pacific Railroad Co., the U.S Supreme Court was tasked with resolving a dispute between two railway companies over their shared use of a bridge across the Mississippi River at Thebes, Illinois. The plaintiff, St. Louis Southwestern Railway Company (SLSW), argued that it had been unfairly charged for its use of the bridge by defendant Missouri Pacific Railroad Company (MPR). SLSW claimed that MPR's charges were unreasonable and discriminatory under sections 1 and 3 of the Interstate Commerce Act because they exceeded those paid by other railroads for similar services on comparable bridges elsewhere in America. The court ruled in favor of MPR, holding that while there may be some differences in rates among different bridges due to varying circumstances such as traffic density or financial obligations related to construction costs, these variations did not necessarily constitute discrimination under federal law unless they resulted from unjust or unfair practices which were not demonstrated here. Furthermore, regarding SLSW’s claim about unreasonableness of rates based on comparison with other bridges’ tolls; Justice Brandeis stated that each case must be judged individually considering all relevant factors including cost structure and economic conditions specific to each situation rather than relying solely on comparisons.

In the dissenting opinion for St. Louis Southwestern Railway Co. v. Missouri Pacific Railroad Co., Justice Stone disagreed with the majority's decision to allow a railroad company to sue another for damages caused by alleged violation of an Interstate Commerce Commission order, without first obtaining a ruling from the commission that its order had been violated. He argued that this approach undermined administrative law principles and could lead to inconsistent court rulings on whether certain conduct constituted violations of agency orders. Furthermore, he contended that it was not within the purview of courts but rather agencies themselves to initially interpret their own orders due to their specialized knowledge and expertise in their respective fields.