Prof. Plumb’s ( :)! ) thesis is quite correct, but noted by observers even in the 18th century. The wool industry was one of the first to arise in the British Isles, followed closely by the first trade restrictions. This harmed Northern Irish wool producers, who responded by importing French Huguenots who brought flax cultivation and developed the new Irish linen industry, farmed out to women throughout the area on a piecework basis. The vagaries of markets and Parliaments of course quickly brought about the first industrial economic downturns, leading to the first of several waves of emigrations from N. Ireland to the American colonies. Thus the Scots-Irish in America.
You are making me pine for my days as a history major in college and to wish that I had time to read books as much as I once did.