The collection includes correspondence, manuscripts, memoirs, diaries, notes, subject files, documents, photographs, and printed materials. Most of the material in the collection concerns Nikolaev's tenure as military attachʹe at the Russian embassy in Washington. Cataloged correspondents include Mikhail T. Florinsky and Geroid T. Robinson. There is a typescript by Vasiliĭ O. Kli︠u︡chevskiĭ, "Kratkoe posobie po russkoĭ istorii." Among the correspondence are cablegrams and official communications to the Russian embassy during World War I and the revolutionary period. Manuscripts, mostly by Nikolaev, concern contemporary and historical military topics. Diaries and memoirs deal with Nikolaev's travels to Europe during World War I and his activities as military attachʹe. Among orders granted to Nikolaev is the "Order of the Sacred Treasure," signed and sealed by the Japanese Emperor Meiji (1911). Printed materials include many articles by Nikolaev.

The collection consists of correspondence, manuscripts, notes, photographs, subject files, and printed materials. Correspondents include Victor Chernov and George Kennan. Extensive notes by Mosely concern European diplomacy in the 1830s and the South Slavic Zadruga. There are thousands of photographs, chiefly from the Soviet Union ca. 1945-1955. Besides photographs of Soviet, Chinese, and East European political figures, such as Mao Tse-Tung, György Lukʹacs, and Boris Spasskiĭ, there are photographs of such Western figures as Enrico Berlinguer and Pablo Neruda. Subject files and mimeographed and printed materials include files on the Inter-University Committee on Travel Grants; papers on Soviet Studies distributed by St. Antony College, Oxford University; State Department research reports, and works by Mosely.