Therefore, the majority of the Irish people found that the South, not the North, was the true land of liberty, offering greater social and economic opportunities and easier access into the overall mainstream of everyday life. Indeed, since before the nation’s founding in the fiery forge of a people’s revolution, the South and its people—not only in the cities but also in the rural areas and in the western frontier regions (as far west as the plains of west Texas)—were fully receptive to the Irish refugees from hard economic times, famines and British oppression.

In total, an estimated forty thousand Irishmen fought for the Confederacy. During the climax of the bloody showdown at Gettysburg, large numbers of Ireland-born Confederates marched forth in lengthy formations that flowed with mechanical-like precision over the open fields during Pickett’s Charge.

I don't understand why this quote didn't point out the vast numbers of Irish soldiers who fought for the North.

The Irish were welcomed enough by both sides who were in desperate need of men. More importantly, men that could fight, and many of these Irish immigrants had either previous experience, or were the sons of, Irish rebels from earlier in the century.

It is also not necessarily true that the Irish were going to be welcomed so kindly by Ulster-Scots (Scotch-Irish), Scots, and English. The Irish could be welcomed, or they could not be, it depends on peoples and times.

Not sure what the point was of the "mechanical-like" comment either. It's not like the Virginians or North Carolinians weren't in the same advance.