This book explores U.S. military surgeons' purposeful efforts to alter howmedical and line officers in the U.S. Army and Navy conceived of disease, appreciated surgeons' roles, and organized medical war preparations through education, training, exposure, and medico-military professionalization between 1884 and 1918. It traces surgeons' postwar efforts to change American military cultures in response to the revelations of the germ theory of disease and deadly typhoid fever epidemics in the American training camps of the Spanish-American War. Medical and line officers required academic education and practical lessons to contextualize disease, surgeons, and medical care, understand and appreciate germs' role in medicine, and train to apply these lessons to benefit their soldiers and sailors. Surgeons also reinforced their scientific education and grew military medicine through postgraduate education and tactical training designed to enhance the line's perception of surgeons and medical science