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
Founder's Hall (Rockefeller University) business, from which he retired in 1897. His efforts at philanthropy were formally guided from 1891 by Frederick T. Gates, a Baptist minister who had previously (1889) recommended to Rockefeller that he establish the University of Chicago. Much of Rockefeller's early philanthropy was on a comparatively small scale, and it was soon clear that larger-scale endeavors needed to be organized to properly guide his charitable giving. Gates suggested to Rockefeller that he establish a medical research institute that would be on a par with major European institutions of the period. In June 1902, Rockefeller made a commitment of $1 million