John and Yoko’s war-is-over billboards spanned a dozen global cities in 1969.

Evidence

On December 15, 1969, an enormous billboard went up in Times Square (and in Los Angeles, Toronto, Montreal, London, Paris, Rome, Berlin, Athens, and Amsterdam) declaring WAR IS OVER! / IF YOU WANT IT / HAPPY CHRISTMAS FROM JOHN AND YOKO. — J. Hoberman, Everything Is Now, 1525

Categorization

• CANDY: A clean, tweetable image: ‘WAR IS OVER! / IF YOU WANT IT’ in ten cities at once — perfect elevator-conversation material about the ambition of late-60s public art.