The U.S. Supreme Court case Baltimore & Ohio Railroad Co. et al. v. Aberdeen & Rockfish Railroad Co. et al., 1968, centered around a dispute over the division of joint rates among railroads in the United States under the Interstate Commerce Act (ICA). The Baltimore and Ohio Railroad Company, along with other Class I Railroads, argued that they were entitled to a larger share of revenues from joint rates due to their higher operating costs compared to smaller Class II and III railroads like Aberdeen & Rockfish Railroad Company who also participated in these hauls but had lower expenses because they operated on shorter routes or less trafficked lines. However, the court ruled against this argument stating that it was not within its jurisdiction to decide how revenue should be divided among different classes of railroads as per Section 15(6) of ICA which gives exclusive authority for such decisions only to Interstate Commerce Commission (ICC), an independent federal agency responsible for regulating interstate surface transportation.

In the dissenting opinion for Baltimore & Ohio Railroad Co. et al. v. Aberdeen & Rockfish Railroad Co. et al., it was argued that the Interstate Commerce Commission (ICC) should not be allowed to establish joint rates without considering whether they are just and reasonable, as required by law. The dissenting justices believed that this case represented a departure from previous decisions which held that the ICC must consider all relevant factors when setting rates, including their impact on smaller railroads like Aberdeen & Rockfish Railroad Co.. They also disagreed with allowing larger railroads to set discriminatory rates against smaller ones through collective ratemaking procedures under Section 5a of the Interstate Commerce Act, arguing it could potentially harm competition in violation of antitrust laws.