Ivanov's manuscript memoirs (550 p.) touch on the following topics: the attempts by the Duma to convince Nicholas II to abdicate in February, 1917; Petrograd in 1917-1918; the Civil War on the Northwest Front, including relations between the Whites and the new Estonian republic (Ivanov also discusses the Northwest Front of the Civil War in a book "O sobytiiakh pod Petrogradom v 1919-om godu" Berlin, 1921.); his internment in the French concentration camp at Vernet in 1939-1940; German use of former White soldiers during WW II; and the war in the Smolensk area in 1942-1943. Notably collection includes typescritp draft of Grand Dukes' Mikhail Aleksandrovich, Kirill Vladimirovich and Pavel Aleksandrovich Manifesto of March 1 1917 (manifesto on granting constitution) with N. N. Ivanov's holograph notes and P. Miliukov's signature. There is also a letter to Ivanov from General Johan Laidoner, commander of the Estonian army.

There are letters from fellow historians, such as John Franklin Jameson and Aleksandr Lappo-Danilevskiĭ; Kadet Party leaders, including Vladimir D. Nabokov and Nikolaĭ Astrov; and others such as Boris Bakhmeteff, Charles Crane, Vladimir Jabotinsky, Louis Marshall, Thomas Masaryk, and Nikolaĭ Roerich. A large correspondence series consists of letters and petitions sent to Miliukov during the Third State Duma (1907-12). Manuscripts include Mili︠u︡kov's memoirs, and his notebooks from the period of the Civil War. There is also a manuscript by Isaak Shkovskiĭ (pseudonym -- Dioneo) on Russian writers and journalists during World War I. Subject files deal with the State Duma, the Civil War, and the emigration.