In the 1950s the "peace sign", as it is known today, was designed by artist and designer Gerald Holtom for a March in Trafalgar Square, London for the British Campaign for Nuclear Disarmament.
Holtom explained the genesis of his idea as follows: "I was in despair. Deep despair. I drew myself: the representative of an individual in despair, with hands palm outstretched outwards and downwards in the manner of Goya's peasant before the firing squad. I formalized the drawing into a line and put a circle round it
The rest, as they say, is history. It has since been adopted by anti-war and counterculture activists in the United States and elsewhere.