He served as administrator of USAID from 1981 to 1987 where he led the U.S. response to the Great Famine in Africa in 1984–85. During that famine, the U.S. delivered 2 million tons of food to Africa in a 12-month period. With UNICEF, he and USAID led the worldwide effort to deal with diarrhea and dehydration, then the biggest killer of children in the developing world. This involved massive increase in the use of Oral Rehydration Therapy (ORT) and saved millions of lives: "At AID, you learn the process of deciding as a group large issues," McPherson said. McPherson's interest in world humanitarian and agricultural issues has made a difference for millions of people. While administrator of USAID he was also chair of the board of the Overseas Private Investment Corporation. McPherson is also widely considered one of the most effective administrators of USAID.
