In the Thornton Burgess collection at the Howard Gotlieb Archival Research Center at Boston University, there is a folder marked "propaganda." We've already touched upon Burgess's association with the "Vigilantes" and his work for Hoover's wartime Food Administration. The folder includes a few more examples, primarily from the same era.
In one piece, for example, Peter Rabbit is pressed into service to advocate "early shopping" for Christmas. (This was apparently an effort by the government to get much needed revenue from sale taxes for war aims, though "Peter" explains it is based on concerns that there wouldn't be enough labor to deal with the holiday rush). [Here's an image from another branch of the same campaign].
Burgess also wrote at least one piece advocating the purchase of Liberty Loans. This time he didn't employ bedtime story characters--his rhetorical tactic was to stress that "You, the individual, are at war." [Here's an image from another branch of the same campaign]
Finally, Burgess wrote on behalf of the Victory Boys and Victory Girls, asking school children to sign a pledge card to volunteer and raise money for United War Work. This would help supply soldiers with "recreation and amusements" (and keep them away from the licentious behavior that would otherwise dominate). [Here's an image from another branch of the same campaign]
Thus Burgess participated in some of the more significant homeland propaganda efforts during World War I. His most famous contribution, however, involved one of his bedtime characters, Happy Jack Squirrel.
Next: Happy Jack's Thrift Club