This collection contains the personal and professional papers of Shmuel Mordkhe Zygielbojm, a Jewish-Polish Socialist politician, Bund leader, member of the National Council of the Polish Government-in-Exile in London, and a labor and political leader. These materials include Zygielbojm’s writings, personal correspondence, clippings, and some photographs. These materials relate mainly to Zygielbojm’s work in London as well as the worldwide reactions after his suicide.