The collection consists of correspondence from such ballet and theater personalities as Sergeĭ Khudi︠a︡kov, Sergeĭ Lifar,́ Nadezhda Nikolaeva-Legat, Alekander Sanin and Vera Trefilova. There is also one letter each from Zinaida Gippi︠u︡s, Nadezhda Teffi, Boris Zaĭt︠s︡ev and Vladimir Zeeler. In addition, there are several typed manuscripts by Pleshcheev, including his book-length biography of E.N. Roschina-Insarova, and clippings of newspaper articles by Pleshcheev.

The papers include correspondence, manuscripts, and printed materials. Correspondence consists of letters from a number of important cultural figures in the emigration, including: Ivan Bunin, Zinaida Guppius, Aleksandr Kuprin, Pavel Mili︠u︡kov, Alekseĭ Remizov, Nadezhda Teffi, and Alekseĭ Tolstoĭ; there are also one or two letters each from Konstantin Balḿont, Dmitriĭ Merezhkovskiĭ, Ili︠́a︡ Repin, Fedor Shali︠a︡pin, and Marina T︠S︡vetaeva. There are manuscripts of several works by Shpoli︠a︡nskiĭ, including his memoirs, "Poezd na tretém puti" (New York, 1954).

The collection includes correspondence from Konstantin Balḿont, Nikolaĭ Evreĭnov, Zinaida Gippius, Georgiĭ Grebenshchikov, Vasiliĭ Maklakov, Sergeĭ Potresov and Nadezhda Teffi. There is one letter each from Boris Bakhmeteff, Vera Bunina, Aleksandr Grechaninov, Aleksandr Kuprin and Alekseĭ Tolstoĭ. The manuscripts include poems and a play scenario by Nadezhda Teffi as well as Roshchina-Insarova's autobiographical essays and article about Sergeĭ Lifar.́ In addition, there are three scrapbooks containing clippings and programs of Roshchina-Insarova's performances, and approximately 40 photographs of her.