No, but something that happened in the 70's can not be one of the foundations of the 60's movement. It is not mathematically possible.
Now if you had said the radical movement or communist movement or the anti-American movement or pro Soviet movement then you would have been correct but time flows only in one direction. (As far as we know. Some people disagree. But they have yet to come back with any proof.)
OK, but this is history and not math. ‘The 60’s Movement’ is a catch-all phrase to describe that whole period of time. Maybe not mathematically accurate, but that’s term that’s used.