Slavery was institutionalized in the Colonies by the English, the Spanish and every other European country for 200 hundred years. The Confederacy only existed for about 4 years. The last Yankee state to abolish slavery was New Jersey about ten years before the Civil War. The Irish immigrants in the early 1860's were snatched up almost before they left the ship to be used as cannon fodder in the Civil War by the hypocrite North.
So are you saying that the Irish who volunteered to come to America suffered worse than the black folks who were brought to this country in chains.
Yes. The Irishman who was sick or injured was left to starve or live on whatever charity was available. He was disposable, a slave was valuable to his owner and would never be left to starve if injured. Frame it any way you want, voluntary immigrants were disposable, expensive slaves were not.