Causes for the Flourishing of Philanthropic Foundations in the United States Li Tao(132) There are so many philanthropic foundations in the United States and their sizes and influence are so noticeable that no parallel can be found in other countries. The causes for the flourishing are the unique historical, religious, cultural backgrounds and the social settings of the times. The rapid economic growth at the turn of the 20th century produced a group of millionaires, or even billionaires who had accumulated huge wealth, thus laying the material foundation for the setting up of large philanthropic foundations. The cultural and religious tradition that advocated donation and denounced greed was the inner drive and the social and political settings at home and abroad the outer drives. All these factors together led to the booming of modern philanthropic foundations in the U.S. Philanthropic foundations, as an important actor in American social and political life, have exerted important influence on American domestic and foreign policies.