The oft quoted line “We have met the enemy and his is us” is the creation of American cartoonist and animator Walt Kelly (1913-1973), who is best known for his newspaper comic strip Pogo. It concerns the adventures of a group of animals living in the Okefenokee Swamp, the main character being Pogo the Possum. Dating from 1948, the strip was a landmark in its use of political and social satire, even being courageous enough to attack Senator Joseph McCarthy’s communist witch hunt hearings by the introduction of a shotgun-wielding bobcat named "Simple J. Malarkey”.
The quote is a parody of a message sent in 1813 from US Navy Commodore Oliver Hazard Perry to Army General William Henry Harrison after the Battle of Lake Erie, stating, "We have met the enemy, and they are ours."
In the foreword to his 1953 book of cartoons, The Pogo Papers, which included the above attack on McCarthy, Kelly wrote:
Traces of nobility, gentleness and courage persist in all people, do what we will to stamp out the trend. So, too, do those characteristics which are ugly. It is just unfortunate that in the clumsy hands of a cartoonist all traits become ridiculous, leading to a certain amount of self-conscious expostulation and the desire to join battle.
There is no need to sally forth, for it remains true that those things which make us human are, curiously enough, always close at hand. Resolve then, that on this very ground, with small flags waving and tinny blast on tiny trumpets, we shall meet the enemy, and not only may he be ours, he may be us.
Walt Kelly first used the quote "We Have Met The Enemy and He Is Us" on a poster for the first Earth Day in 1970:
In 1971, he did a two panel version with Pogo and Porky in a trash filled swamp:
There is also a later colour version of the second panel:
In 1972, it was the title of a book, Pogo: We Have Met the Enemy and He Is Us: