Dagenhart (P) had two children. Although classified as minors, they were able to work in a cotton mill in North Carolina. Congress then passed the Child Labor Act, which would have led to their firing. This Act prohibited the shipment in interstate commerce of any product produced or mined by child labor. P brought action on behalf of his children to deny the enforcement of this act. He named as defendants the Attorney General, Hammer, (P) and the company that fired his children. The district court enjoined the enforcement of the Act. D appealed.