Eykyn Maclean, a New York and London-based gallery, facilitated the sale of the Mandela portrait.
The anonymous buyer said about the portrait: "I am honored to own what has already become an iconic image of one of the greatest statesmen the world has ever known. In a single frame the photographer has captured the essence of dignity, principle, conviction and courage in this great man from whose life's work and dedication to a greater cause we all have much to learn, and by which I am inspired daily."
The construction of a children's hospital has been a longheld dream of Mandela's and before he fell ill he had campaigned for funds for its construction. The state-of-the-art hospital is scheduled to open late in 2014 and will be a 200-bed facility providing world-class pediatric care.
Mandela, 95, is in critical but stable condition, under intensive medical care at his Johannesburg home, after being discharged in September from a lengthy hospitalization.