On Apr. 3, 1879, John B. Hamilton began service as Supervising Surgeon (later known as U.S. Surgeon General), succeeding fellow Army veteran and Chicagoan Dr. John Woodworth, the first Supervising Surgeon. Woodworth had died in office, amidst a political battle with the fledgling American Public Health Association and its allies in Congress over the possibility that a new National Board of Health would supercede the newly revamped Marine Hospital Service (MHS), predecessor to the National Institutes of Health, established in 1798.

Tha fact that MHS outlived the National Board of Health and emerged in the 1890s reinvigorated is a testament to Hamiltonﾒs skills as a political negotiator and managert. Under his tenure, MHS gained authorities to establish a national quarantine on sea and land (interstate), formal recognition of merit-based requirements for a Commissioned Corps of medical officers, and a new laboratory devoted to bacteriology, the newest public health science of the day.