I would start with social security information: The SS death index should be on Ancestry:
"Q9: What information is available from Social Security records to help in genealogical research?
A: You might want to start by checking out the Social Security Death Index which is available online from a variety of commercial services (usually the search is free). The Death Index contains a listing of persons who had a Social Security number, who are deceased, and whose death was reported to the Social Security Administration. (The information in the Death Index for people who died prior to 1962 is sketchy since SSA's death information was not automated before that date. Death information for persons who died before 1962 is generally only in the Death Index if the death was actually reported to SSA after 1962, even though the death occurred prior to that year.)
If you find a person in the Death Index you will learn the date of birth and Social Security Number for that person. (The Social Security Death Index is not published by SSA for public use, but is made available by commercial entities using information from SSA records. We do not offer support of these commercial products nor can we answer questions about the material in the Death Index.)
Other records potentially available from SSA include the Application for a Social Security Number (form SS-5). To obtain any information from SSA you will need to file a Freedom of Information Act (FOIA) request."
from
https://www.ssa.gov/history/hfaq.html