In the case of Moore v. Terminal Railroad Association of St. Louis, 1958, the U.S Supreme Court ruled in favor of a black railroad worker who was denied a promotion due to his race. The plaintiff, Robert L. Moore had been working for the defendant company as a laborer and applied for an open position as Yard Brakeman but was rejected because he was African American while white employees with less seniority were promoted instead. He filed suit under Section 3(a) of Executive Order No. 9981 which prohibits racial discrimination within federal contractors' employment practices and won at both district court level and circuit court level before reaching the Supreme Court. The main issue addressed by this case revolved around whether or not executive orders could be enforced through private lawsuits brought by individuals affected by violations - something that hadn't been definitively settled prior to this point in time. Ultimately, it was decided that they indeed could be enforced in such manner thus setting precedent for future cases involving similar issues thereby strengthening civil rights protections across America's workforce particularly those employed by federal contractors.

In the dissenting opinion for Moore v. Terminal Railroad Association of St. Louis, Justice Frankfurter disagreed with the majority's decision to uphold a lower court ruling that found the defendant guilty of violating antitrust laws by denying plaintiff access to its railroad terminal facilities in St. Louis. He argued that there was no evidence presented showing an intent or actual effect of monopolization on part of the defendant and thus, it did not violate any antitrust laws under Sherman Act Section 2 which requires proof of such conduct for conviction. Furthermore, he contended that this case should have been decided based on principles governing common carriers rather than anti-trust law as it involves issues related to public utilities regulation and interstate commerce.