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
John D. Rockefeller North America and settled down in Germantown, Pennsylvania. The name Rockenfeller ("from Rockenfeld") refers to "Rockenfeld" in the district of Neuwied. In 1864, Rockefeller married Laura Celestia "Cettie" Spelman (1839–1915), daughter of Harvey Buell Spelman and Lucy Henry. They had four daughters and one son together. He said later, "Her judgment was always better than mine. Without her keen advice, I would be a poor man." The Rockefeller wealth, distributed as it was through a system of foundations and trusts, continued to fund family philanthropic, commercial, and, eventually, political aspirations throughout the 20th century. John Jr.'s youngest son David Rockefeller