Walter Reed is best known for his research demonstrating that the mosquito is responsible for transmitting yellow fever from infected humans to uninfected humans. In its emphasis on sound scientific methodology, his work set the standards for twentieth-century experimental medicine.

Reed was born in Belroi, Virginia. He received an M.D. from the University of Virginia in 1869, and another from Bellevue Hospital Medical College in New York, New York in 1870. After briefly practicing medicine, he was commissioned in the United States Medical Corps in 1874, serving at frontier posts in the West. In 1898, Reed was appointed chair of a board to investigate typhoid fever in army camps. The board was able to show that typhoid is spread by flies and contact with fecal material, bringing an end to the epidemic.

In 1900, Reed was appointed head of the Commission of the United States Army on yellow fever in Havana, Cuba...