Hello Danielle It was a slogan during the sixties promoted by the "Hippies" who wanted to react to the war in vietnam. The real meaning is "Faites l'amour pas la guerre" in French, in english it means "make love to each other and don't make war to each other" It was a good motto at the time.

it was a phrase coined in the 60's to promote peace.

you already answer it PEACE cowboy...