In this issue of Social Science History we begin a special series of articles surveying the impact and use of historical research and reasoning in the other social sciences—anthropology, economics, geography, political science, and sociology. The authors of the essays have been asked to analyze their disciplines so that readers will get a sense both of major issues and research directions and of influences. In addition, they have been asked to include in their references older important works as well as more recent ones, so that those in other disciplines may use the essays as bibliographic sources. After the series is completed, we expect to publish an expanded version of it as a separate book.