The National Labor Relations Board (NLRB) (defendant) exercised jurisdiction over lay faculty members at two groups of religious high schools owned by the Catholic Bishop of Chicago and the Diocese of Fort Wayne-South Bend, Inc. (plaintiffs). The NLRB certified certain unions as the bargaining agents for these teachers and ordered the schools to bargain with those unions. Additionally, charges of unfair labor practices were filed against the schools under the National Labor Relations Act, 29 U.S.C. §§ 151-69. At a hearing before the NLRB, the schools argued that the challenged practices were mandated by the schools’ religious creeds and that the NLRB could not exercise jurisdiction over church-operated schools. The NLRB disagreed and ordered the schools to cease the challenged practices and enter into collective-bargaining agreements with the unions. The schools challenged the NLRB’s order in the United States Court of Appeals for the Seventh Circuit. The court of appeals held in favor of the schools and declined to enforce the order. The NLRB petitioned the United States Supreme Court for review.