English: This photo portrait is of Dr. Alexander D. Langmuir (1910 - 1993), chief epidemiologist at the Centers for Disease Control and Prevention for two decades. Dr. Langmuir founded the Epidemic Intelligence Service (EIS) for disease investigations in 1951. Langmuir was a strong proponent of "shoe leather" epidemiology: an intense focus on the people and places where the disease outbreaks actually occur and the precise gathering of statistics to support whatever action is needed. In starting this EIS program at the CDC, his goal was to introduce professionals from medicine and relevant social sciences to the science of epidemiology in the hope that they learn about public health. As a result, many of these “disease detectives” continued on in the field of epidemiology, while others carried that knowledge with them into whatever careers they chose and were advocates for sound public health.