Who led the conquest of yellow fever?

Answer 1

If you are referring to the disease:

US Army physician Walter Reed is largely credited with the campaign that "beat" yellow fever, but Reed credited Cuban Dr. Carlos Finlay for his success. Finlay gave the mosquito hypothesis, which proposed that mosquitoes are the disease's vector, rather than direct human contact as previously thought. Walter Reed led the expedition that confirmed this hypothesis to be true. The physician William Gorgas then applied Finlay and Reed's work to eradicate yellow fever from Havana, and later on, help keep yellow fever at bay amongst the workers of the Panama Canal.