This paper analyses the theory of philanthropy by F. P. Keppel and the historical role of the private foundation ""Carnegie Corporation of New York"" in American adult education. Keppel who is the 5th president of Carnegie Corporation suggested the national association of adult education ""American Association for Adult Education"". His idea also held the plan of reform of his cooperation. Carnegie cooperation was looked critically with American society, because the big powers of the cooperation were a threat to the powers of the states. He had to sweep away the criticisms of cooperation and be trusted in American society that the cooperation had the social mission to work for the public good. For that reason, he made his theory of philanthropy. And he decided to support for adult education for the social mission of the corporation. The examination of his theory of philanthropy is highly suggestive for investigate of idea of national association of adult education organized by private foundation.