America is at a tense moment in history. We're living at a time of stark disagreement. Some say the president doesn't tell the truth; others say he tells it like it is. This tension came to head in Charlottesville, Virginia, where confrontations between white nationalists and counter-protesters erupted in violence. Documentary filmmaker Ken Burns says these rifts aren't without precedent: the Vietnam War also sparked divisions in American society. In today's "Two Way Street," Burns takes us back