Well Rosanna,Lennon more thsn any other Beatle led the anti-war movement. So it could have been him.
It could have been Marvin Gaye in his song "What's Going On" but that was 1973 and unless no one said it before that,it may be him.
Could've been Martin Luther King or even Muhammed Ali. Those are the most likely people but who knows,it could have even been just a protester at a rally.
------------------
"A knight of the road,going back to a place where he might get warm."
- Borderstone