In the late nineteeth century, 15% of US physicians were homeopathic physicians. The American Medical Association (AMA) was seriously threatened clinically, philosophically and economically by homeopaths. As distinct from other unorthodox practitioners, homeopaths graduated from respected medical schools. The AMA was so threatened by homeopathy that from 1860 to the early 1900s a conventional physician would lose their membership in the AMA if they simply consulted with a homeopath. The AMA and drug companies also applied pressure on various funding sources so that the homeopathic schools had difficulty staying alive.