During the late 19th and early 20th centuries, AMM staff engaged in various types of medical research. They pioneered in photomicrographic techniques, established a library and cataloging system which later formed the basis for the National Library of Medicine (NLM), and led the AMM into research on infectious diseases while discovering the cause of yellow fever. They contributed to research on vaccinations for typhoid fever, and during World War I, AMM staff were involved in vaccinations and health education campaigns, including major efforts to combat sexually transmissible diseases.