 In 1973 Blum founded the Catholic League for Religious and Civil Rights and served as its president until 1989.Modeled on the American Civil Liberties Union and Anti-Defamation League, the Catholic League sought to safeguard the religious freedom and free speech of Catholics.In 1983 Pope John Paul II recognized Blum's service by naming him a Knight of the Equestrian Order of the Holy Sepulchre of Jerusalem.