Tennessee Secondary School Athletic Association (Association) (plaintiff) was a non-profit private membership corporation organized to regulate interscholastic sports among public and private high schools in Tennessee that were members of the Association. Although schools were not forced to join, almost all of the state’s public schools, and many of its private schools were members as there was no other interscholastic sports regulatory authority in the state. The Tennessee State Board of Education even recognized the Association as the primary regulatory agency in the state for high school sports, and their voting membership was almost exclusively composed of public high school administrators. In 1997, the Association brought a regulatory enforcement proceeding against Brentwood Academy (defendant), a private member school. Brentwood was charged with improperly recruiting new students for its sports teams, and was given a large fine and suspension by the Association. Brentwood Academy then sued the Association after sustaining these penalties in federal court under 42 U.S.C. § 1983, alleging that enforcement of the recruitment rule against it was a state action and a violation of the First and Fourteenth Amendments to the United States Constitution. The district court entered summary judgment for Brentwood Academy, but the court of appeals reversed. The United States Supreme Court granted certiorari.