Kilroy was here is a meme that became popular during World War II, typically seen in graffiti – though its origin predates its use in graffiti by several decades.[1][2] Its origin is debated, but the phrase and the distinctive accompanying doodle became associated with American G.I.s in the 1940s: a bald-headed man (sometimes depicted as having a few hairs) with a prominent nose peeking over a wall and with his fingers clutching the wall.