Involving more than 550,000 U.S. troops by the end of it, the escalation of the war in Vietnam brought social and political polarization home. It was televised so the more Americans saw of the war, the more unpopular the conflict became.

"The lads from Liverpool" led a musical cultural exchange that impacted everything from fashion to sexual mores to politics. Graham Nash, Smokey Robinson and more recall what it was like to make music that mirrored the souls of the young.