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
Nelson Rockefeller 1935–40. From 1932 to 1979 he served as a trustee of the Museum of Modern Art, where he also served as treasurer, 1935–39, and president, 1939–41 and 1946–53. He and his four brothers established the Rockefeller Brothers Fund, a philanthropy, in 1940, where he served as trustee, 1940–75 and 1977–79, and as president in 1956. Rockefeller was a patient of famous psychic Edgar Cayce. Rockefeller served as a member of the Westchester County Board of Health, 1933–53. His service with Creole Petroleum led to his deep, lifelong interest in Latin America. He became fluent in the Spanish language. In 1940,