Kilroy was here

Kilroy was here is an American popular culture expression that became popular during World War II; it is typically seen in graffiti. Its origins are debated, but the phrase and the distinctive accompanying doodle – bald-headed man (sometimes depicted as having a few hairs) with a prominent nose peeking over a wall with the fingers of each hand clutching the wall – became associated with GIs in the 1940s.

"Kilroy" was the American equivalent of the Australian Foo was here, which originated during World War I and later became popular amongst schoolchildren.

"Mr Chad" or just "Chad", was the version that became popular in the United Kingdom. The character of Chad may have derived from a British cartoonist in 1938, possibly pre-dating "Kilroy was here".

Etymologist Dave Wilton says, "Some time during the war, Chad and Kilroy met, and in the spirit of Allied unity merged, with the British drawing appearing over the American phrase." Other names for the character include Smoe, Clem, Flywheel, Private Snoops, Overby, The Jeep (as both characters had sizable noses), and Sapo.

Author Charles Panati says that in the United States "the mischievous face and the phrase became a national joke... The outrageousness of the graffiti was not so much what it said, but where it turned up." The major Kilroy graffiti fad ended in the 1950s, but today people all over the world still scribble the character and "Kilroy was here" in schools, trains, and other public areas.

It is believed that James J. Kilroy was the origin of the expression, as he used the phrase when checking ships at the Fore River Shipyard in Massachusetts during WWII.

The phrase may have originated through United States servicemen, who would draw the doodle and the text "Kilroy was here" on the walls and other places they were stationed, encamped, or visited. An ad in Life magazine noted that WWII-era servicemen were fond of claiming that "[w]hatever beach-head they stormed, they always found notices chalked up ahead of them, that 'Kilroy was here'".

Brewer's Dictionary of Phrase and Fable notes that it was particularly associated with the Air Transport Command, at least when observed in the United Kingdom. At some point, the graffiti (Chad) and slogan (Kilroy was here) must have merged.

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