Osteopathy was founded by Andrew Taylor Still, M.D. (1828 - 1917) in 1874 in reaction to what he perceived as inadequate medical treatment of his day. Specifically, he believed that medications tended to be over prescribed and that such medications were often toxic in nature.

He intended his new system of medicine to be a reformation of the existing 19th century medical practices he knew and imagined that someday "rational medical therapy" would consist of manipulation of the musculoskeletal system, surgery, and very sparingly used drugs. He invented the name "osteopathy" by blending two Greek roots osteon- for bone and -pathos for suffering in order to communicate his theory that disease and physiologic dysfunction were etiologically grounded in a disordered musculoskeletal system. Thus, by diagnosing and treating the musculoskeletal system, he believed that physicians could treat a variety of diseases and spare patients the negative side-effects of drugs.

Early in the twentieth century, the American osteopathic profession adopted the use of medicine and surgery. As biomedical science developed, osteopathic medicine gradually incorporated all its proven theories and practices. D.O.'s have been admitted to full active membership in the American Medical Association since 1969.