The papers comprise correspondence, documents, institutional files, writings, lectures, memoirs, research notes, photographs, third party materials, printed materials, periodicals, microfilms, audio material, and digital files accrued by historian and professor emeritus of Columbia University, Leopold H. Haimson, during his professional life.
The series comprises reel-to-reel tapes with materials from the Menshevik Project and some tapes that may not be related to it. Arranged in 3 subseries.
Includes interviews with Georgian Mensheviks and reels entitled "Russian interviews" that may not be related to the Menshevik project. Arranged alphabetically.