Dr. Clarence Rees and Dr. Clair Stealy founded the Rees-Stealy Clinic in 1923. They wished to offer to the community improved medical care by coordinating the talents of many specialists in a single facility. This had been done very successfully at Mayo Clinic, Oxner Clinic, Cleveland Clinic, and others in the United States, and the organization started at Rees-Stealy was similar. The Medical Group has operated continuously keeping pace with the rapid advancements in health care delivery, medical practice, and medical technology. It has grown from two doctors to over 300 in 77 years.

In 1938 Dr. Rees and Dr. Stealy looked to the future, and felt that many improvements in health care might result from fundamental biomedical research and its relation to daily clinical problems. They recognized the Clinic's unique position in the community as a center for comprehensive medical services and established Rees-Stealy Medical Research Fund, the forerunner of the present Rees-Stealy Research Foundation. The goal was clear at that time and has been up to the present, to investigate the biomedical problems and promote the advancement of medical knowledge.