The Irish population has yet to recover fully fom the 'potato famine' that killed about 1.5 million and caused another 1.5 million to emigrate in the 1800's.
Ireland is the only modern/developed country to have a lower population today than in 1840.
You didn't learn that history in school either.
Albeit, Germany is the European country to have more of its citizens emigrate to the USA than citizens from any other European country.
The Irish Famine killed Protestants as well as Catholics.
Yet it is the latter who have claimed the Famine as their own.