One of the earliest memes dates all the way back to World War II.

If you were a U.S. soldier in WWII, chances are, you saw this drawing everywhere. Known as “Kilroy,” he popped up on graffiti all around the world during the war.

Becoming a symbol of hope and a source of laughter for the soldiers. U.S. soldiers drew the WWII meme everywhere, from the washrooms to the battlefield. Kilroy would appear on anything foreign in Europe or Japan.

The drawing was reassuring, since it meant another U.S. soldier had been there. It all started with an American shipyard inspector named James Kilroy.

He inspected rivets on ships and left checkmarks to denote they had been seen. Riveters got paid for each checked rivet. If they erased Kilroy’s marks, riveters could get checked a second time – resulting in double pay.

To prevent this, Kilroy drew a picture, and wrote “Kilroy Was Here” in bold letters. When the U.S. joined WWII, ships left quickly, and ‘Kilroy’ never got erased.

Soldiers saw it and found it funny. They started to draw it everywhere. After the war, Kilroy became more than a drawing.

He appeared in movies, commercials and even songs. Kilroy is much harder to spot today, most have been painted over or faded over time.

But U.S. soldiers still keep the tradition alive without the vandalism.And if you look closely, you can spot one at the WWII memorial in Washington.