My uncle, who was an FBI agent during the 60s and 70s, found out the peace symbol was brought over from Britain and represents the semaphore signals for the letters N and D, which stood for Nuclear Disarmament espoused by Bertrand Russell and other like-minded academics. My uncle’s job was to find out who was funding the protests or the printing of publicity material and as we all know now, the KGB played a very significant role.
It’s an older symbol than that. It’s history was posted on a thread this morning but I can’t remember which one. I have a “leaky” brain.