The Irish situation becomes more fascinating the more deeply you look into it. Newspaper articles and even advertising from the mid 19th through the early 20th century are very revealing. The Irish were portrayed invariably as drunken, diseased, lazy, Catholic, and not the sort of decent people one would associate with. This went for both sides of the Atlantic.
If you’re interested, this New Yorker article reviews a groundbreaking book by Noel Ignatiev called, “How the Irish Became White.” He not only explores the “not quite fully human” idea that kept the Irish in a position where starving them to death was morally acceptable, he became one of the first academics to study the construction of whiteness and white privilege — through a process of examining how the irish finally “became white” in the 20th century.