Legal Question in Real Estate Law in Illinois

Your starting point to avoid spending too much would be to obtain a title search to determine the status of ownership, mortgages, liens, etc. That would help you determine if it is worth starting matters with an attorney or would give you information to bring to an attorney.

Other assets would be more difficult to search since you do not have anything to go on (bank records, life insurance statements, etc.). You might try to search the state's abandoned property site now and then. For Illinois: https://icash.illinois.gov/

I would also search the court website to see if there are any pending cases (foreclosure, probate, collections, ...). You do not say where everyone lived, but if the zip code you used is any indication, then you would want the Cook County Circuit Court Clerk (http://www.cookcountyclerkofcourt.org/?section=CASEINFOPage&CASEINFOPage=2400 ). If not, then do an online search for the court clerk for the county and state involved Perhaps search for each person involved and be careful to try the searches various ways as some sites work differently than others (try last name only, maybe first initial, unless that yields too many results, all lower case).

You should also type each of their names into several search engines and see what else comes up. Then follow those leads.

Ultimately, you could petition to probate the estate and then use your powers as administrator to access the home, search for records, contact banks, etc. In this situation, I do not see going this route without an attorney, but then you need to determine if it is worth spending the money.

I agree generally with Mr. Repay but would say this too: decide how much you want to spend on this expedition. There are potentially multiple probate cases, at least one title search for chain of ownership (going back 40 years) and that's just scratching the surface. There are statute of limitation issues as well even if your lineal ancestors had assets and died intestate (ie. without wills). So I first would sit down with the information you have, put together some kind of family tree with names, relationships, dates of death, etc. (even if there are gaps....) and bring it to a reputable genealogist and/or probate attorney to discuss. That way you can get a sense of what will be needed. A good place to start could be with the family home. But here's my ultimate point: when you find out what you find out, and unless you come across something that is of significant benefit - what is your goal? Tracing assets into (potentially) multiple collateral relatives' hands or into nothingness, or attempting to locate any collateral relatives to attempt to reconstruct the family you feel you lost? Based on personal experience, I can tell you the former could be a folly and the latter could be reliving the original abandonment, and you need to be prepared for whatever happens. You apparently had your mom's family for most of your life and hopefully she did good by you.