The term "wop" was not originally a "racist" term. It originally was a term used by Immigration&Naturalization personnel on Ellis Island. When potential immigrants would debark the boats, they would be classified as either " with papers " OR "without papers "depending on whether they had been pre-screened in Europe or not. Those without papers would be screened separately and provided with an admission sheet that would be stamped W.O.P. or "with out papers". At the time that this system was being used, the vast majority of immigrants without papers were of Italian origin. W.O.P. had nothing to do with their nationality, color, race, etc. The general public mis-understood this and assumed that the term WOP was a derogatory term, when in fact it wasn't originally intended to be so.
