Corporate philanthropy is considered to be an integral part of corporate social performance; however, this was not always the case. At one time, the use of corporate funds for philanthropy was illegal. This article uses institutional theory to examine the evolution of corporate philanthropy from its illegal status to the time when it became both legal and expected behavior on the part of business firms. Because institutional rules rarely change as dramatically as did those governing corporate philanthropy, an examination of these changes provides a unique opportunity to begin development of more generalized theory concerning change in the institutional structure of business.