Such work, bordering on the cartoon, provided a profitable avenue for social commentary. An American example appeared in the illustration to a children's book of 1880, where a dog dressed as a ruffian stands on the straw, cudgel in hand, warning off a cow and her calf (see above). It ushers in use of the theme in illustrated papers a little later. J. S. Pughe's centrefold in "Puck" pictures a dog in the uniform of a U.S. Marine holding off European nations that wish to participate in the Nicaragua Canal scheme. It was followed by the cover cartoon of "Harper's Weekly" picturing William Jennings Bryan as the dog, obstructing the choice of the Democratic presidential candidacy and preventing others getting at the White House oats.