Beginning in 1914, the Rockefeller Foundation's International Health Commission (which became the International Health Board in 1916 and the International Health Division in 1927) committed itself to the project of eradicating yellow fever. Its efforts were modeled on the sanitary techniques deployed by US sanitarians in Havana in 1901 and, more importantly, during the construction of the Panama Canal between 1904 and 1914, with mosquito control preeminent among them. William C. Gorgas, who led these campaigns and then came to work for the Rockefeller Foundation, argued for a key center approach to yellow fever eradication that targeted the remaining urban endemic foci of infection, with the assumption that once these seed beds of the disease were eliminated, yellow fever would fade from the planet. But as the IHB conducted campaigns in South America, Central America, and West Africa during the late 1910s and 1920s, they discovered that yellow fever's ecology and epidemiology were more complicated than they had assumed, and that a "key center" approach would not work to eradicate the disease. By the 1930s, and particularly with Fred Soper's discovery of sylvan or jungle yellow fever, the Rockefeller Foundation gave up on their eradicationist dream
