The rise and flourishing of public interest funds in the U.S. is rooted in American social and cultural tradition, the mature market economy, and the healthy and sound environment of the rule of law. A unique concept of public charity exists in American society as a result of the social and cultural traditions, thus becoming the ideological origin of spontaneous donation and the establishment of public interest funds. All these provide sufficient sources of funding and strong intentions of donation for the development of public interest fund.