As told by the late Lowell Hardin, former professor of economics at Purdue University and officer at the Ford Foundation in the early 1960s, many of the original centers of today‘s CGIAR were conceived in the daily exchanges of two neighbors traveling to work each day to New York City. They were George Harrar, the first leader of the Rockefeller-Mexico program and then president of the Rockefeller Foundation, and Forrest (―Frosty‖) Hill, then vice president of the Ford Foundation. As a result of their exchanges of ideas the Office for Special Studies in Mexico evolved into the Centro Internacional de Mejoramiento de Maíz y Trigo (CIMMYT, Texcoco, Mexico), and later in the 1970s its potato program was included in the newly launched Centro Internacional de la Papa (CIP, Lima, Perú). In 1967, two multi-crop centers with alike names in English and Spanish but with clearly distinct agro-ecosystem geo-domains were added to what later was to be known as the Consultative Group on International Agricultural Research (CGIAR). These centers were Centro Internacional de Agricultura Tropical (CIAT) in Cali (Colombia) and the International Institute of Tropical Agriculture (IITA) in Ibadan (Nigeria). IRRI, CIMMYT, CIAT, IITA and CIP were the first international centers of the CGIAR network that today includes other 10 institutes worldwide, addressing a broad range of issues in agriculture: fishery, forestry, livestock, water and other natural resources management, plant genetic resources, research capacity building and food policy.

In October 1963, Harrar and Hill visited Nigeria to explore the feasibility of such international undertaking. The visit was followed by an extensive tour around the country by Richard Bradfield, an agronomist of the Rockefeller Foundation, and Frank Moore, a program specialist in agriculture at the Ford Foundation in Nigeria, and together with Donald Kingsley, the Ford Foundation representative in Nigeria, recommended the establishment of the Institute ―on or adjacent to the campus of the University of Ibadan‖. In December 1963 the Ford Foundation Board authorized its staff to submit the proposal for such an international organization to be jointly funded by both Foundations.

Throughout 1964 and 1965, David Heaps, the new country representative of the Ford Foundation, had extensive exchanges on the proposal with the Government of Nigeria, which published a notice of its intention to acquire the land in the Official Gazette of 23 December 1965. In March 1966 the agreement was reached on the objectives, organization, funding, tax status, land needs, and other matters, and IITA was thus established. That same year the Ford Foundation appropriated US$ 5 million for the building IITA‘s headquarters on land at Ibadan, donated by the Government of Nigeria
and named Will Martin Myers as the first director–designate. His tenure was short lived when in early 1967 Myers left IITA to take up the post of vice president of the Rockefeller Foundation. Although civil war broke in Nigeria, the construction of IITA began in 1967 under the leadership of the first Director General of IITA Herbert R. Albrecht –a leading agronomist from the University of Wisconsin–Madison and former president of North Dakota State University– with the backstopping of Haldore Hanson from the Ford Foundation in Nigeria.

The strong commitment by the Government of Nigeria since 1963 was key to keeping IITA headquarters in Nigeria despite the political turmoil and civil war. Another exhibition of commitment was the legal status given by the Government of Nigeria to IITA both as its inception with Decree No.32, and later with the signing of the headquarters agreement included in the 1991 Diplomatic Immunities and Privileges Order. In 1992 the Government of Nigeria issued a million copies each of four commemorative stamps to mark the silver jubilee of the Institute.