M. Thomas Inge, Comics as Culture, pg. 138

…Contrary to popular belief, the comics did not thrive because of the immigrant readers who knew little English. A good command of the language was necessary to get the point of much comic strip humor, especially things like the street urchin dialect of The Yellow Kid or the mock-German dialect of The Katzenjammer Kids.

M. Thomas Inge, Comics as Culture, pg. 138