The collection consists of correspondence, manuscripts by Messner and others, memoirs by Messner, photographs and printed materials. Manuscripts by Messner include a typescript (275 p.) entitled "Nekotorye prichiny porazhenii︠a︡ Germanii v voĭnu 1939-1945 g.g." Messner's memoirs (3293 p. and 350 p.) cover the years 1914-1973. Included among them are clippings, photographs, mimeographed materials and pamphlets. The majority of his memoirs concern World War I and the Civil War. Photographs are mostly copies. Printed materials consist mostly of clippings of articles by Messner in South American monarchist periodicals.

The papers consist of correspondence, manuscripts, photographs, a subject file, and printed materials. The correspondence includes a letter from Randall Thomas Davidson, Archbishop of Canterbury, and one from Nikolaĭ Roerich. There is an essay about Metropolitan Platon by I︠O︡ann Chepelev, and a number of photographs depicting church officials and White army leaders. There is a subject file concerning Platon's meeting in 1919 with President Wilson. The collection also contains articles and clippings by and about the Metropolitan, and there are several books and pamphlets as well. The materials were collected by his daughter and grandson; many of the items are photocopies.

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 papers consist of manuscripts and printed materials. The manuscripts include an autobiographical essay, Pronin's memoirs about Generals Kornilov and Brusilov, an essay about an attempt to murder Trot︠s︡kiĭ and articles on the Russian emigration in Yugoslavia and Brazil. The printed materials include copies of the journal "Vera i vernost,́" Pronin's pamphlet "Krymskai︠a︡ voĭna -- Oborona Sevastopoli︠a︡" and "Vo imi︠a︡ pravdy -- O belom dvizhenii i ego vozhdi︠a︡kh," to which Pronin and others contributed.