Of what I know of the term "Black Irish", it was and is used to
describe Irishmen in the South, primarily Cork, who have skin darker than
the usual Celtic skin and black, curly hair. This is believed to be the
result of intermarriages with the Spaniards who landed there after loosing the
Battle of the Spanish Armada in 1588, too ashamed to return to Spain
defeated, and only able to find refuge in Catholic Ireland. However, the
term has become so widely used that it may now just be a name to describe
Irishmen with black hair, who may have no relation to these Spaniards.
Remember it is possible to be full blooded Celtic and have black hair (e.g.
Donald the Black from Scottish history). The Irish immigrants to America
may have used this term, as you said, in the pejorative, because those
with black hair may have seemed more "Mediterranean" than the other Irish
immigrants, and, we must unfortunately recall, many of the immigrants,
prejudiced against by the nativites, were prejudiced themselves.
Matthew O'Craudhlaoich (Crowley)
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