  In 1966, Benjamin published the landmark The Transsexual Phenomenon and that same year saw the opening of the Johns Hopkins University program for sex-reassignment surgery, ushering in a period of large university-based gender-identity clinics which lasted until the end of the seventies. By the closing of Johns Hopkins in 1979, the Harry Benjamin International Gender Dysphoria Association (since renamed The World Health Professional Association for Transgender Health or WPATH) had been formed and had approved standardized criteria for the treatment of transsexuals. A year later, transsexualism was added to the DSM.