I understand what you say about your Jonathan Edward Prosser's 1880 census data showing that his father "James" was born in GA, and his mother "Frances" was born in SC. Unfortunately, he or whoever answered the enumerator's question simply gave the wrong data.Let's look at the situation in more detail for your Prosser line, each of the following were sons of your James Prosser - and this is what each said in the 1880 census:John Duke Prosser said Father = NC, Mother = TN; John Edward Prosser said Father = GA, Mother = SC; Berry Prosser said Father = VA, Mother = NC; Andrew Prosser said Father = NC, Mother = VA; Jesse F. Prosser said Father = VA, Mother = VA; William P. Prosser said Father = NC, Mother = TN.... So - you can see the picture, so I'll stop here. Bottom line is that the census data is unreliable.
I am very confident that your James Prosser, my William B. Prosser, and Jesse Prosser are indeed brothers. However, after I have fully investigated and researched Otey Prosser, I can assure you that James, William B., and Jesse are not children of Otey Prosser the Revolutionary War Vet. A simple search in this message forum will quickly prove to you that we do not descend through Otey.
I am also very confident that all three were in fact born in NC, and I am just as confident that their father whoever he was - was also born in NC. I am on a regular basis finding early Prosser's in NC in various court records - even though they do not appear in census records... They are indeed there, and we will find the right one some day.