Peter Viereck's "Kilroy" appeared in his first collection of poetry, Terror and Decorum: Poems 1940-1948, published in 1948. The poem's title is taken from the phrase "Kilroy was here," popularized during World War II to draw attention to the wide scope of territory on which American soldiers landed or which they occupied during the conflict. The name "Kilroy" represented every GI from the United States, and thousands of soldiers scrawled the phrase on walls, tanks, latrines, train cars—virtually anything that would accept a marking. The graffiti's appearance in so many likely and unlikely places made a loud statement about the mighty American presence in Europe, Asia, and the South Pacific islands where GIs fought, killed, died, and were held captive. Soldiers from all the enemy nations were familiar with the phrase and, obviously, were not too happy to see it turn up nearly everywhere they looked.

Viereck's poem emphasizes not only the daunting American presence in World War II, but also the spirit of adventure with which the culture hero Kilroy was associated. Through allusions to several historical and mythical figures who were widely traveled and gallantly successful in one way or another, Viereck portrays the World War II American soldier as a courageous, romantic globetrotter— a swashbuckling daredevil unafraid of strange lands and a far greater man than the sedate suburbanite who was not up to the same noble challenges. "Kilroy" incorporates legendary adventures from Roman mythology, Marco Polo's travels, even Chaucer's Canterbury Tales and Dr. Faustus. These heroes (or anti-heroes) are compared to allegorical figures with negative names—Can't, Ought, But, and so forth—as a form of praise and admiration for the soldier who did his duty not with blind submission and formality but with a flare for the exotic experience and a hearty appetite for both danger and victory.