Revel Oliver (plaintiff) leased his own truck to interstate carriers and drove it for them. Oliver belonged to the Local 24, International Brotherhood of Teamsters Union (codefendant). The collective-bargaining agreement (CBA) between the local Teamsters council and an association of carriers (codefendant) set rental rates that independent owner-drivers could charge carriers and the drivers’ wage scale. Since 1938, the union had tried to control rental rates, claiming they did not cover operating costs. Owner-drivers paid the difference, meaning they effectively earned less than union wages. Oliver sued the union and carriers’ association in Ohio state court, but the union backed Oliver in challenging the provision. The court found the provision violated Ohio antitrust law because it fixed prices for leasing trucks used in commerce. The union countered that Ohio could not override a collective agreement as to wages under the National Labor Relations Act (NLRA). But the court concluded that the NLRA did not permit a “remote and indirect approach to the subject of wages” and entered a permanent injunction barring the minimum rental rate for Oliver’s truck. The Supreme Court granted review.