Family Law Questions? Ask a Family Lawyer Online.
I will try to best answer your question.
If the asset you're seeking a transfer was jointly owned with a right of survivorship all you should need is the death certificate. If the asset is not owned with jointly with a right of survivorship you will need to open up an estate in the US in order to establish who has authority to handle your father's affairs. If there is a will, assets will be distributed in accordance therewith. If there is no will, assets will be distributed according to the intestate laws where your father last resided in the US.
I hope this information is helpful and I wish you the best of luck.
Sure. Type into Google search engine Illinois state intestate law of succession. This will give you a plethora of information on the topic