I assume you are refering to Pete Maxwell son of Lucian Maxwell of the Maxwell Land Grant fame.  There are several genealogies of Pete Maxwell around and most all of them are fabrications of the truth. There are certainly no decendents bearing the surname of Maxwell of Pete Maxwell himself but it seems likely that there descendent with the Maxwell surname of the older brothers of Lucian. Louis Serna is married to a descendent of Paulita Maxwell Maxwell who was Pete Maxwell's daughter and I understand he wrote a genealogy of that descent so it might prove worth getting in touch with Louis Serna. Google him and you will find him on the web. Clearly lots of Maxwell folk in the United States would like to claim descent from the land-rich family of Lucian Maxwell but in truth there are none (unless they have changed their surnames....!)  In genealogy, it make sense to go backwards from people you know are your ancestors rather than trying to link forwards from someone famous because it really is just not going to happen! Your forfathers might have told you that they were related to Pete Maxwell but the likelyhood is that they had no idea who their forefathers were. Genealogical research is not that difficult but it is time-consuming. It is highly unlikely that you will be able to prove your descent sitting in front of the computer. You will have to go out and look for written records.  Go out and find a birth record for your father and you should find out who his father was. There are around 100,000 living Maxwells in the world today so do not assume you are closely related to any famous ones and you will probably be able to find your true forefathers.