- Max Theiler (above) of the Foundation’s Virus Laboratory in New York City wins the Nobel Prize in medicine and physiology for developing the yellow fever vaccine.
- The Foundation initiates broad-scale support for research in genetics with grants to establish centers and build entire departments at the California Institute of Technology, Johns Hopkins University, the University of Chicago, the Massachusetts Institute of Technology, Stanford University, Columbia University, universities in Indiana, Texas, Wisconsin and many locations abroad.
- A Foundation supported cooperative agricultural development program, similar to that developed in Mexico, begins in Colombia under Dr. Lewis M. Roberts.
- The Foundation begins its support of historical research in areas of contemporary significance. Over the next decade, it will spend nearly $7 million to support research, including interdisciplinary and interpretive work including that done by the scholars Toynbee, Braudel and Barraclough and the editing and publication of papers of American statesmen: Hamilton, Madison, Lincoln and Wilson.
- John Foster Dulles becomes Chair of the Board of Trustees and serves until 1952.
- A decade of awards begins to scholars in international relations and in legal and political philosophy.
- John D. Rockefeller III becomes chair of the board of trustees and serves until 1971. Dean Rusk becomes president and serves until 1961.
- A $112,000 grant enables Dorothy Thomas and Simon Kuznets to undertake the first analysis of US population change, capital formation and economic activity.
- Harvard’s School of Public Health receives the first Foundation grant for a family planning project. In 1960, Johns Hopkins receives the second.
- The mosquito carrying yellow fever is eradicated from 13 major Latin American countries as an outgrowth of Foundation methods developed in Brazil in the 1930s.
- The Foundation supports the Growth of American Families project, the first of the national fertility studies now carried out every five years with US government support.
- The Foundation begins a program of institutional support in the arts. Grants help found the American Shakespeare Festival in Stratford, Connecticut, and support drama and other arts at Karamu House in Cleveland, one of the nation’s leading interracial centers for drama and other arts.
- The government of India requests that the Foundation send a population advisory mission. The group recommends an approach that addresses maternal and child public health. A year later, India becomes the first nation to adopt an official family-planning program.
- “Corn production in Mexico has increased steadily since 1947,” reports Dr. J. George Harrar, the architect of the Rockefeller Foundation's agriculture program, later to become the Foundation president. “The country [has] been able to meet the demands of increasing population since 1947 without resorting to the importation of this basic food from abroad.” During this period, Mexico becomes a net exporter not only of corn, but of wheat and other cereals.
- The Foundation reestablishes relationships with former fellows now behind the iron curtain, awarding new fellowships and making grants in Poland for laboratory and library equipment.
- The Population Council receives the first of many grants, spanning 39 years and totaling more than $40 million.
- Through the New School for Social Research, the Foundation grants $10,000 to writer and neighborhood activist Jane Jacobs for research into the relationship between function and design in urban environments. She receives another grant the following year for $8,000. The book resulting from that research, Jacobs’ masterpiece, "The Death and Life of Great American Cities," is published in 1961.
- The Foundation receives a bequest of the Villa Serbelloni on Lake Como, Italy. The villa, set among 50 acres of park and gardens, becomes the Foundation's Bellagio Study and Conference Center, hosting international conferences and scholars in residence.