Historic Physician Epidemiology Leader and One Health Advocate Dies D. A. Henderson, MD, MPH, the great American physician who directed the eradication of small pox in the 20th century and a strong supporter/advocate of the One Health concept, died August 19, 2016.   Dr. Henderson served on the One Health Initiative Autonomous pro bono team’s (OHI) Advisory Board  Early in the development of the OHI’s campaign to promote the One Health approach to worldwide public health and clinical health (comparative medicine), Henderson expressed strong support and encouragement.   April 22, 2007 Dr. D. A. Henderson, legendary leader of the worldwide smallpox eradication program said:   “I thank you for your email and congratulate you and your colleagues in promoting the One Medicine [now generally referred to as One Health] concept. It is an initiative that is long overdue but, at the same time, I dont personally identify dramatic solutions that are apt to change the landscape in the short term. I would note that when one has had the good fortune to have enjoyed the tutelage of *Jim Steele during my tenure at CDC and periodically ever since, as a friend, the one medicine concept becomes well engrained. Indeed, when I came to Hopkins as Dean in 1977, I cast about to determine how we might link up with a veterinary school for research and educational purposes. Unfortunately, geography was simply too great a hurdle to overcome.   Bottom line: I would be more than happy to do whatever I could in support of your efforts.”    *Note Dr. James H. Steele [DVM, MPH]: