The local paper had an article about St Patrick's Day foods. First up is Corned Beef and Cabbage, which is only sort of Irish. It used to be called a New England Boiled Dinner. Corned beef was packaged in Ireland, yes, but it was packed for export. The Irish didn't get to see most of it, as they were too poor. But being in such constant contact with something nice you couldn't have made it a very precious food in their eyes, so when people made a little money, first in America and then back in Eire, it was eaten with great joy. It became traditional for special occasions. Makes complete sense to me. If I was employed making something valuable that I couldn't have myself, that would loom large on my list of desirable items.
Also listed was the Reuben sandwich. I love Reubens and might make them for St Pat's Day if they're now traditional. They sound completely authentic, don't they? Marbled rye bread from Cork. Sauerkraut from County Winslow. Swiss cheese from the Irish Alps. Thousand Island dressing from the St Lawrence River in Irish Canada (though some consider Russian dressing to be more authentic).