What is the origin of the phrase "What, me worry"? (It isn't Mad Magazine!)

In Dead Wake: The Last Crossing of the Lusitania, Erik Larson discusses the early history of the submarine. According to Larson, the submarine was regarded as an "iron coffin" until the work of John Philip Holland, an Irish engineer.

Larson says (page 57): "A famous 1898 cartoon, based on a photograph....shows Holland emerging in top hat [actually it may have been a derby] from the hatch of one of his submarines with the caption "What, me worry?" For the photograph on which the cartoon may have been based, see Wikipedia, John Philip Holland

I have not been able to find the cartoon; nor have I been able to find if the phrase was in use before 1898, or if it originated in the cartoon.

(See also Richard Compton-Hall The Submarine Pioneers: The Beginnings of Underwater Warfare, Chapter Three.))

According to John E. Hett, Publisher and Editor of The Journal of MADness, they have their origins in anti-Irish racism prevalent in the late 18th century and throughout the 19th century in Great Britain and the US. http://www.madmumblings.com/forum/viewtopic.php?t=3592