This book would not be possible without the generous support of Williams College and the Stanley Kaplan Program in American Foreign Policy. The editors wish to extend special thanks to Carrie Greene, Director of Commencement and Academic Events, and James McAllister, the Fred Greene Third Century Professor in Political Science, who cohosted the 2018 conference, One Hundred Years of Communism in the USA, on which this volume is based. The editors also wish to thank each other for their hard work, humor, and comradeship in both organizing the conference and editing this volume.