Many Irish, on the other hand, had a much harder time integrating into American society, especially the Irish that arrived from the time of the infamous Potato Famine on. (The earlier Scots Irish immigrants, though, did integrate extremely well into US society; these earlier Irish immigrants were among the earliest people that started the westward migration of Americans.) The later Irish immigrants couldn't speak English well, were extremely poor and their Catholicism strongly clashed with the more dominant Protestants in the USA; as a result, the later Irish immigrants were heavily discriminated against even well into the 20th Century. Al Smith, the 1928 Democratic nominee for President, lost because even in 1928 people were not ready to accept someone who was Catholic and of Irish immigrant descent to be President.
You ain't seen Irish until you come down to Kearny Avenue in Kearny NJ. THE BEST fish and chip joints on earth :)