The Mayo brothers and Harvey Cushing: a review of their 39-year friendship through their personal letters.

Mayo Clinic founders, William J. Mayo and Charles H. Mayo, and Harvey W. Cushing were among the most significant pioneers of modem American surgery. A review of their personal correspondence reveals a special relationship among these three individuals, particularly between William Mayo and Cushing. Their interactions within the Society of Clinical Surgery initiated their close personal and professional association, which would endure for 39 years. William Mayo strongly supported Cushing's efforts to develop the specialty of neurological surgery, and Cushing sought Mayo's advice in making important career-related decisions. Their supportive friendship and professional alliance remains an example for future generations of neurological surgeons.