Buchanan was Mass General’s General Director from 1982 to 1994, and one of the leaders of the formation of Partners HealthCare (now Mass General Brigham). Before his service to Mass General, he had a wide-ranging medical career. He started out in endocrinology, served in the U.S. Army Medical Corps in Korea, was a professor and then dean at Weill Cornell Medical College, and professor and then associate dean at Pritzker School of Medicine of the University of Chicago. Under Buchanan’s leadership, Mass General expanded its research facilities into Charlestown Navy Yard, created the Proton Beam Center, oversaw the early development of the MGH Institute of Health Professions, and reinstated the obstetrics department after a 50-year gap.