This dissertation argues that knowledge based on personal experience came to rival accredited knowledge in American foreign policymaking during the Vietnam War. This shift toward experiential authority transformed American political culture and foreign policy. First-person narratives of Americans who lived abroad became crucial sources for popular understanding and congressional decision-making. In turn, the authority of personal experience in discussions of foreign policy helped enable a movement away from the global projects of development and containment and toward human rights around the world.

Focusing on Vietnam veterans and Peace Corps volunteers, this dissertation explores the uses to which these groups put their on-the-ground experience when they spoke publicly about American foreign policy issues. By examining veteran testimony before the Senate Committee on Foreign Relations and returned Peace Corps volunteer activism about American policy in the developing world, this study finds that the authority of personal experience acquired great persuasive power in the context of a nation reeling from the failure of its foreign policy abroad and wary of its political leaders' integrity and ability. This crisis in accredited authority and consequent shift toward experiential authority had lasting impacts both on American political culture and the foreign policies Americans pursued in the post-Vietnam era. By examining a distinct language of political participation, this study provides a new lens through which to interpret the events of the late 1960s and early 1970s.