This study seeks to resolve differences between various types of political leaders and to link broad historical patterns with the idiosyncratic circumstances of individual lives and careers--to integrate the micro and the macro levels of understanding in the field of leadership studies. To accomplish this task, a vast array of previous scholarship and primary documents has been assembled and drawn into new combinations. Equivalent data on all U.S. presidents enable an unprecedented internal comparison within this select group. Comparison with parallel data, developed for other types of leaders, permits U.S. presidents to be analyzed in comparative perspective for the first time. Against this background, the study creates a unique collection of medical and psychological profiles for the entire set of presidents--a body of data that allows us to discover new combinations and patterns of presidential traits.American presidents emerged from this study looking very much like other political leaders in terms of social background and preparation for a political career. But contrary to myth, the authors found U.S. presidents to be puzzingly unexceptional--even average--in their personal and career characteristics. For other types of leaders, the authors had found distinctive combinations of traits and experiences that seemed to account for their political leadership roles. For the presidents, such combinations seemed elusive, even confounding. They did conclude, however, that presidential leadership is firmly anchored in the cultural, sociological, and historical contexts from which it emerges.