I was contacted by an attorney from Africa. He believes that I may be the descendant of a family that uses my same sir name. Do I have to prove that I am? If he processes this inheritance and I receive the money, what does the US government require from me? What if the attorney is wrong? Am I held liable at a later date?

It's a SCAM!!

This is an extremely well know and documented "Advanced Fee Fraud" or 419er.