This comprehensive history of the YIVO Institute for Jewish Research--a groundbreaking American Jewish cultural organization, library, and research center--details its longstanding efforts to preserve eastern European Jewish culture during a century of genocide and mass emigration. Through YIVO's steady commitment to establishing itself in New York and the broader United States, Yiddish language learning and the study of eastern European Jewish history and culture became a crucial part of post-Holocaust Jewish life. Focusing on the institution's transitional period from 1940 to 1970, the book explores how YIVO charted a course for scholarship and public engagement that remained true to its founding ethos--"from the folk, for the folk, and with the folk"--while acclimating to American society and mainstream Jewish culture.