The publishers of four Los Angeles daily newspapers (defendants) refused to engage in collective bargaining with a union representing the “newsboys” who distributed their newspapers. The union filed an unfair labor charge against the publishers with the National Labor Relations Board (NLRB) (plaintiff). The NLRB rejected the publishers’ contention that the newsboys were not entitled to the protections of the National Labor Relations Act (Act) because they were not “employees” within the meaning of the Act. Under the Act, employers must engage in collective bargaining with their employees. Congress did not define the scope of the term “employee” in the statute. The United States Supreme Court granted certiorari.