Papers include correspondence, manuscripts, documents, photographs, subject files, and printed materials. The extensive correspondence relates to Mogilat's personal and professional activities and includes letters from many of her students and colleagues. Correspondents include Gleb Struve, Alexandra Tolstoy and Boris Unbegaun. Of special interest are letters by her first husband Baron von Taube, written from the front during World War I, and correspondence with various Russian acqaintances about the Soviet Union in the 1920s and 1930s in which they describe life in a communal apartment, and plans to rescue friends who have been arrested. Subject files concern Columbia's Russkiĭ Kruzhok and the Avtonomoff method of teaching Russian to Americans. There are letters, photographs, concert programs and music of Russian emigre composer and pianist Ariadna Mikeshina. Manuscripts are by various persons; most are by John Paul Mihaly, who had been Mogilat's student. There is also a manuscript of translations by Clarence Manning, "Four Poems by Blok." Documents and photographs concern Mogilat and her family, both before and after emigration. Printed materials consist mostly of off-prints of articles by Clarence Manning and others, primarily on literary topics. There are also books, mimeographed materials, periodicals, and clippings.

ROVS North America (ROVS-N.A.) Records consist of correspondence, manuscripts, documents, photographs, organizational records, subject files, and printed materials. There are also papers of the Paris-based Sovet Rossiiskogo Zarubezhnogo Voinstva (Council of the Russian Military Abroad) and other emigre military and political organizations active in New York, San Francisco, Los Angeles and South America. The cataloged correspondence includes letters by Evgenii Miller, Nikolai Tsurikov, Aleksandr Kutepov and other emigre figures and by Richard Nixon, Lyndon Johnson, Barry Goldwater and other prominent American politicians. Arranged correspondence series consist of general office files, Paris-New York files, correspondence of Aleksei von Lampe and Vladimir Vitkovskii and topical correspondence files. Among the manuscripts are short articles and reminiscences by various people. There are photographs of Evgenii Miller, Nicholas II and of emigre organizational gatherings during the 1950s and 1960s. The organizational records include circulars, bulletins, orders, memoranda, reports, publications and financial records for ROVS and the Sovet Rossiiskogo Zarubezhnogo Voinstva. Subject files concern such topics as the Elisavetgrad Military Academy, the Union of the First Kuban Campaign, the Gallipoli societies, the Ingermanlandskii Regiment and the Russian Anti-Communist Center in New York. The printed materials include a book by Boris Kuznetsov and publications and circulars from other emigre organizations.

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.