Nothing new here. Google "Thomas Nast Irish" images.
Here's one:
http://www.greatcaricatures.com/articles_galleries/nast/html/1871_0902_irish.html
[...]arm yourselves to the teeth; if you or any one belonging to you be injured by any assault whatever, take the law into your own hands, for the law refuses you protection, and shoot down the Orange dogs as you would the commonest vermin that afflict your premises.No wonder there was such a feeling toward the Irish.