The papers include correspondence, subject files, photographs, and printed materials. The majority of the collection concerns the mission of the American Red Cross to Russia in 1917-1918; Thacher served as a secretary of the mission. There are letters and telegrams by W.B. Thompson and Raymond Robins, records of supplies, shipments, and distribution reports and over 600 photographs from Russia, China, and Romania. There is substantial correspondence from 1918-1919 concerning Russia, including letters by Louis Brandeis, Felix Frankfurter, and Lillian Wald. A substantial part of the collection concerns Russian war relief in 1941-1942, an area in which Thacher was active. Printed materials include a pamphlet and an article on Russia prepared by Thacher after his return from that country in early 1918.

The collection -- composed of correspondence, manuscripts, documents, photographs and printed materials -- sheds light on the anti-Bolshevik campaign in the Kuban ́region, Siberia and the Far East. The correspondence is chiefly from the early 1920s and includes letters from Viktor Pokrovskiĭ to his brother Boris. Among the manuscripts are biographical sketches of Viktor Pokrovskiĭ, especially accounts of his assassination in Bulgaria in 1922; information circulars sent out by Ataman Grigoriĭ Semenov, "Commander in Chief of the Far Eastern Armies;" and reports written by Boris Pokrovskiĭ on events in Europe, particularly Eastern Europe, and the Far East. The documents are comprised primarily of decrees (prigovory) from local Kuban ́Cossack groups and the photographs are chiefly portraits of Viktor Pokrovskiĭ. Included among the printed materials are clippings from the Russian and emigre press, a large number of Civil War broadsides and political pamphlets published in Siberia in 1919. Several of the latter are by and about Ataman Semenov.