[Wallace T.]

In this country the Irish hardly suffered at all. Their troubles, such as they were, was due to their Catholicism. Italians, German Catholics, Poles, and others had the same issues. Genetically, the Irish different little from the Highland Scots or the Welsh, who are Celtic in culture as well. DNA shows the Irish as little different from the British as a whole and even other Northwestern European people. Scottish and Welsh Americans are considered WASPs, even though their status is due to their Protestant background, not their DNA.
That being said, the legitimacy of their persecution in the Old World has nothing to do with their complaints today The same applies to blacks and Jews.

[IronJack]

They were, if not "persecuted" in this country, at the very least greatly disenfranchised and marginalized. To be fair, so were many Italians and Poles from roughly the same era. American society, contrary to the "melting pot" rhetoric, has always resisted the introduction of new ethnicities, although conformity to the American ethic -- hard work, honesty, humility, grace -- tends to expedite their eventual assimilation.

Segregation, either externally or internally imposed, disrupts that assimilation and perpetuates hostility. It is not the responsibility of the majority to conform to the expectations of the minority and the former rightfully resents being forced to do so.