In 1974, the last of the 50 states passed legislation licensing chiropractors. Yet organized medicine continued to limit the ability of chiropractors to practice freely. In addition to fighting legislation designed to allow chiropractors to receive private insurance reimbursement, the AMA banned contact between chiropractors and allopaths, making it impossible for chiropractors and allopaths to refer patients to each other. In response, chiropractors and their supporters filed antitrust suits in the late 1970s against the AMA, various state medical associations, the American Hospital Association, and several other representatives of organized medicine (as well as the AOA), alleging that these organizations had restrained trade illegally. Chiropractors and their defenders eventually won or favorably settled out of court every suit. As a result, overt opposition to chiropractic ended.