His family fortune derived from Gulf Oil, Westinghouse, BNY Mellon, Koppers, Alcoa and others.
[2] He attended Princeton University for one year, worked for his family's company, Mellon Financial, and served in the OSS during World War II.
Mellon owned and operated a cattle ranch in Arizona until, at the age of 37, he read about, and then studied, Albert Schweitzer's medical missionary work in Gabon, and resolved, with Schweitzer's encouragement and guidance, to create a similar third-world hospital.
He and Gwen Grant Mellon enrolled at Tulane University; he received his medical degree in 1954 at the age of 44, and she became qualified as a medical-laboratory technician.
[1] Mellon died in Deschapelles at the age of 79 from cancer and Parkinson's disease, on August 3, 1989.