at least here in the US (I don't know how much you would normally learn in Belgium), you learn about immigration as waves of immigrants coming to the US and about there being some resistance to those immigrants. But not necessarily all the details about the Irish, Italians, Jews, Slavs, etc were treated in the 1840s-1920s period. Things may be different for damookster in terms of Italian-American knowledge based on his history. Just as it is for me for Jewish history based on growing up in NYC.
I am not Italian-American nor Italian. I personally have no problem with Columbus Day because I recognize what Europeans were like in the 15th century. And I don't look at the Natives with some rosy glasses either. The Aztecs in particular were one of the more horrifically violent civilizations. Everyone was a product of their time. So when people try to replace Columbus Day with Indigenous Day, I would ask those people to tell me what they know of those civilizations. I think if they knew about the violence then may change their tune. Charles C. Mann's 1491: New Revelations of the Americas Before Columbus is a great book to discuss many things that don't get learned about on either side of the Atlantic.