It’s the summer of 1971 and tourists flock around one of Washington DC’s most famous hotspots – the Capitol steps. Journalist Art Goldberg recalls ‘a squad of soldiers moving through the space. They are grubby-looking troopers, clad in jungle fatigues. Jumping a low fence, they begin shouting at a group of tourists. “All right! Hold it! Hold it! Nobody move. Nobody move!” Their voices full of tension and anger. A man runs from the crowd.