Greetings Paul,

It's possible that your Mahoneys may have emigrated from Ireland to Canada first, and then, some years later, moved on to SC...So, there may be some Canadian records.

What else have you found in NC & SC on this family? It's intriguing that James P. Mahoney was a circuit rider. Do any records or diaries exist from him -- sometimes such things are in an archives or library far from where they rode.

For Frances, church records might have clues to add to the early censuses. They could lead to probate/wills of Frances, and her husband...
James P. Mahoney's siblings would merit looking into also.

Best of luck in your search,
Barb G.