Ive talked to some Irish guest workers, and they all talk like you-laugh at anyone in the US who thinks they are really Irish. That may be true of a lot of people who are partially Irish in the US-probably 40-50 million people at least........but there are many pockets in the midwest and northeast where you see people who are 100% irish.
Boston would be one area, a town i lived in had Irish immigrants that came over to build a canal in the early 2oth century-most of their descendants today are 100% irish, as the town is probably 99% irish catholic.
People in Ireland are short little fuckers compared to the irish over here-must be nutritional differences. Irish genes vary a great deal for such a small number of people-a lot of dwarfs but ive seen some giants.