text: I don't know that I would consider them a failed experiment.  They served the people of the time.  The ethnic parishes kept Catholics together and in the Church through those first years in America; they often built schools, also tied to the Church.  Their identity was as [Ethnic]-American Catholics; their children went to those Catholic schools.  Without those parishes, I suspect a good many of those people could have been gone before the first generation was, lost in a crowd of "others" with no real sense of loyalty.  Especially when their "home" countries were antagonistic or at open war with each other.