This listing is for a signed photo of Loyal Davis, MD (1896-1982); he was a legendary neurosurgeon and stepfather to Nancy Reagan, making him father-in-law to President Ronald Reagan.  Dr. Davis is credited with being the founder of the field of neurosurgery, as well as a founding member of the American Board of Surgery.  He served as Chief of Surgery at the Northwestern University medical school in Chicago for more than thirty years.