Brief Description: Correspondence with individuals including Salo Baron, Bernard Baruch, Sidor Belarsky, Ber Borochov, Judah Leob (Leib) Cahan, Jacob de Haas, Mendl Elkin, Ben Zion Goldberg, Alexander Harkavy, Ephim Jeshurin, Yudel Mark, Kalman Marmor, Henry Morgenthau, Melech Ravitch, Zalman Reisen, Edward Sapir, Max Weinreich, Uriel Weinreich, Yehoash. Correspondence with organizations. Family correspondence. Letters from former students. Biographical materials, such as curriculum vitae, autobiographical notes, I.D. cards, letters of recommendation. Financial records. Clippings of Joffe's publications, of articles about him. Reports, minutes, plans, memoranda and correspondence relating to the Great Dictionary of the Yiddish Language. Materials relating to the YIVO Institute. Notes of Executive Committee meetings. Notes on Board of Directors meetings. Materials of the Research and Training Division. Materials on YIVO Annual Conferences. Materials on the YIVO in Vilna. Materials relating to Joffe's courses and lectures: notes on Yiddish courses, Yiddish composition, phonetics, morphology, etymology. Materials relating to the following topics: dictionaries; Russian literature and linguistics; Old-Yiddish language and literature; the Bove-bukh by Elias Levita (Elia Bachur). Materials relating to music, musicians, Yiddish songs, music institutions, recordings. Folklore materials: folksongs, proverbs, anecdotes.