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.

Her memoirs recount her childhood and education in Russia as a member of a Baltic-German family, her life in Finland after the February Revolution, her service as a nurse in St. Petersburg during World War I, and as a member of a Red Cross mission charged with caring for prisoners of war in Kiev and Moscow during the Civil War. She also describes her arrest and imprisonment in 1919 as well as her brother's experiences in Li︠u︡bi︠a︡nka prison during World War II. The memoirs (416p.) are in the form of a carbon copy typescript and are accompanied by original photographs. Also included in the collection are reprints of several articles published by her husband, Helmuth Stegman, in the 1960's.

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.