Many have confused "Irish" with "Scots-Irish". Both of these groups immigrated from the Island of Ireland but are totally different groups. The "Irish" were Catholic and from the "South" of Ireland where the "Scots-Irish" were from Northern Ireland or "Ulster" and were the descendents of Scots from Scotland and were Protestant (Primarily Presbyterians).
Both groups were "Celts".
There's a little Welsh in there too. Reading the family history, they certainly wouldn't have qualified for the peace prize.