Is he alive or dead? You give so little information as to make it impossible to answer your question....go hire a detective to find out where he lived, where he died, who is closest kin are, etc.
My answer is not intended to be giving legal advice and this topic can be a complex area where the advice of a licensed attorney in your State should be obtained.
I agree with what's been said before. The only other things would be to check with the State where your uncles died (assuming he has passed) and they can direct you to where you can get a copy of his death certificate which will give you the County of his residence at death. Once you have that information, you can check the County probate office to see if a Will or a Petition for Administration has been filed.
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