David Rockefeller his graduate studies, he received a Ph.D. from the University of Chicago in 1940. After completing his studies in Chicago, he became secretary to New York Mayor Fiorello La Guardia for eighteen months in a "dollar a year" public service position. Although the mayor pointed out to the press that Rockefeller was only one of 60 interns in the city government, his working space was, in fact, the vacant office of the deputy mayor. From 1941 to 1942, Rockefeller was assistant regional director of the United States Office of Defense, Health and Welfare Services. Rockefeller enlisted in the U.S. Army
Rockefeller family were particularly prominent in this area. The family was honored for its conservation efforts in November 2005, by the National Audubon Society, one of America's largest and oldest conservation organizations, at which over 30 family members attended. At the event, the society's president, John Flicker, notably stated: "Cumulatively, no other family in America has made the contribution to conservation that the Rockefeller family has made". In 2016 fifth-generation descendants of John Sr. criticized ExxonMobil, one of the successors to his company Standard Oil, for their record on climate change. The Rockefeller Brothers Fund and the Rockefeller Family Fund both backed