In 1915, William Henry Welch and Wickliffe Rose submitted a report to the Rockefeller Foundation that became the template for public health professional education in the United States and abroad. Based on the Welch-Rose Report's recommendations, the Foundation awarded a grant to Johns Hopkins University in 1916 to establish the first independent graduate school of public health, with Welch serving as the founding dean. The Welch-Rose Report and, by extension, the Johns Hopkins School of Hygiene and Public Health established and transmitted a new model of scientific training that wove the laboratory mindset together with the methods of public health administration and epidemiologic fieldwork. During the School's first quarter-century, faculty and alumni were remarkably active in frontline public health problem-solving, as well as launching public health agencies and schools of all types and sizes. The most lasting contribution of the Welch-Rose Report and the Johns Hopkins School of Hygiene and Public Health, now the Johns Hopkins Bloomberg School of Public Health, has been to “cultivate the science of hygiene” to bring about exponential growth in the evidence base for public health. The schools that have adopted the Johns Hopkins model of public health education worldwide have produced professionals who have worked to achieve wide-ranging reforms dedicated to preserving life, protecting health, and preventing injury across populations and continents.