VonsyatskyVonsiatsky died of [[coronary thrombosis]] on February 5, 1965, in [[St. Petersburg, Florida]] at Mound Park Hospital, at 66. His body was interred at West Thompson Cemetery in [[Thompson, Connecticut]].
Many of the documents of VonsyatskyVonsiatsky were stored in the archives of the Hoover Institution in California, in the collection of Professor John Stephan, author of ''The Russian Fascists: Tragedy and Farce in Exile, 1925–1945'',<ref>{{Cite book |url=https://www.worldcat.org/oclc/283384694 |title=Stephan (John J.) Collection |oclc=283384694 |access-date=2022-02-25 |archive-date=2015-02-21 |archive-url=https://web.archive.org/web/20150221211244/http://www.worldcat.org/oclc/283384694%26referer%3Dbrief_results |url-status=live }}</ref> and [[Providence College]], Phillips Memorial Library.<ref name="brownpapers"/><ref>{{Cite book |url=https://www.worldcat.org/oclc/424626155 |title=Guide to the Anastase A. Vonsiatsky and Marion B. Ream papers 1861-1970 |oclc=424626155 |access-date=2022-02-25 |archive-date=2022-02-25 |archive-url=https://web.archive.org/web/20220225065150/https://www.worldcat.org/title/guide-to-the-anastase-a-vonsiatsky-and-marion-b-ream-papers-1861-1970/oclc/424626155?referer=brief_results |url-status=live }}</ref>
