The Irish who are scattered everywhere. During the Great Famine, the Irish had three choices: emigrate to anywhere, go into the workhouses, or die. (More on the Great Famine later).
Many chose to emigrate. Some went to England, particularly to Liverpool, but the largest numbers of immigrants went to the United States, Canada and Ireland. Now, there are more than 40 million people of Irish ancestry in the United States - 5 times the number of people in Ireland during the Great Famine. The map below (from tweakyourbiz.com) shows the scattering of the Irish throughout the world.
image from tweakyourbiz.com