Series I principally consists of Jefferson School materials, but also contains some material from the Workers School and from the Communist Party, and includes course outlines and related readings, bibliographies, pamphlets published by the school, unpublished typescripts, correspondence and unpublished writings of Henry Black, speeches by William Z. Foster, including several given along with William F. Dunne in 1931 at the Workers School's National Training School (for Communist Party cadre), student scrapbooks (steel strike, 1949), pamphlets and briefs concerning the Subversive Activities Control Board's decision to list the school as a Communist-front organization, and a file of Communist Party Farm Commission minutes and other documents from 1946. The authored pamphlets include works by Herbert Aptheker, Howard Selsam and Doxey A. Wilkerson. Unpublished writings include Henry Black's book-length Fundamentals of Subject Cataloging, A Guide to Marxist Studies (a bibliographical introduction) by the editorial board of Science & Society, and The Seattle General Strike of 1919, an apparently contemporaneous participants' account. There is also an incomplete set of the Library Service to Labor Newsletter (ALA), 1949-1954.

Series II contains the following seven indexes (on 3x5 card files) to the Jefferson School Library's periodical and pamphlet holdings (with the bulk of the entries covering the years 1944-1955): Earl Browder Articles, 1922-1944; Pamphlets; Periodicals; Poems; Portraits (Photographs); Reviews (Drama, Motion Pictures); Short Stories.