While MD schools have followed the development of society, osteopathic medicine is a more recent development. The first MD school in the United States opened in 1807 in New York. In 1845, the American Medical Association was formed, and standards were put into place, with a three-year program including lectures, dissection, and hospital experience. In 1892, frontier physician Andrew Taylor Still founded the American School of Osteopathy in Kirksville, MO as a protest against the present medical system. A. T. Still believed that the conventional medical system lacked credible efficacy, was morally corrupt, and treated effects rather than causes of disease. Throughout the 1900s, DOs gained practice rights and government recognition. The first state to pass regulations allowing DOs medical practice rights was California in 1901, the last was Nebraska in 1989. Up through the 1960s, osteopathic medicine was labeled a cult by the American Medical Association, and collaboration by physicians with osteopathic practitioners was considered to be unethical.