Sassenbach library was named after Johannes Sassenbach (12 October 1866 – 19 November 1940), a German trade unionist, SPD politician and co-founder of the trade union publishing and library activities. He worked intensively in favour of trade union education and in 1891was chairman of the Allgemeiner Deutscher Sattlerverein (German Saddlers' Association) and from 1902 to 1919 member of the Generalkommission der Gewerkschaften Deutschlands (General German Trade Union Commission), becoming its secretary in 1922. Between 1906 and 1921 he was secretary of the Internationale Vereinigung der Sattler und verwandter Berufe (International Federation of Saddlers' Unions), from 1923 secretary and between 1927 and 1931 secretary general of the International Trade Union Confederation. He was also a municipal councillor (1906–1915) and from 1920 to 1923 chairman of the Volkshochschule Gross-Berlin. After the abolition of the democratic rule of law by the National Socialist regime, he was arrested on 7 May 1934 for "activities endangering the state" and charged with high treason. As a publisher and journalist and the first bibliographer of trade union writings, he had a large private library, which in 1927 he gave to the Berlin local committee of the Allgemeiner Deutscher Gewerkschaftsbund – ADGB (General German Trade Union Federation) as a study library. In 1931 the local committee acquired the Sassenbach library. The union assets were seized on 2 May 1933 and those of the SPD on 10 May, the day of the book burning. Among the items seized was Sassenbach's library, which was stored with the archives, catalogues and libraries of banned labour organizations in the Haus des freigewerkschaftlichen Dachverbandes Allgemeiner Deutscher Gewerkschaftsbund in Berlin, now occupied by the Deutsche Arbeitsfront (German Labour Front – DAF). In January 1934 the archives of the NSDAP and DAF were also stored there. In October 1934, the library was moved with the NSDAP archives to Munich, where it remained until the end of the war. In 1947 most of the library was transferred via the Munich Central Collecting Point to the Offenbach Archival Depot (OAD), where it was probably divided up, with the result that most of the library is regarded today as lost. After the dissolution of the OAD, some of the contents ended up in the Stadt- und Universitätsbibliothek Frankfurt am Main (Frankfurt municipal and university library), taken over from the Hessian Ministry of Culture and Education, which had been holding them in trust. Other parts of the library went to the Federal Archives in Berlin and the library of the Friedrich-Ebert-Stiftung in Bonn.
Provenance research in 2011 identified a book from the Zweigbibliothek für Geschichte der Medizin an der Universitätsbibliothek der Medizinischen Universität Wien for restitution to the Friedrich-Ebert-Stiftung in Bonn, the legal successor of the former Sassenbach library. The separatum has the ex libris "Bibliothek Sassenbach – Ortsausschuss Berlin des A.D.G.B." and a stamp "NSDAP Parteiarchiv". It is not clear how the book was acquired by the library of the Department of the History of Medicine.