Unlike America's Jewish immigrants, of whom more than three-quarters were skilled workers, the Irish came from an overwhelmingly rural background.

Citation needed. My understanding is that most skilled jobs, outside the garment industry, were closed to Jews in Europe until the late 19th century. From that point on, things changed. I won't quibble over "more than three-quarters" vs. 67% (the figure I found), but if you're going to talk about the Irish in the 19th century, you should compare like with like.