"A Shocking and Seminal Event"

"That division was made all too clear as hundreds of anti-war protesters marched through New York City four days after Kent State. A large group of construction workers taunted them as anti-American and then attacked with crowbars in what became known as 'The Hardhat Riot'. Dozens were injured but President Richard Nixon understood the political advantage of siding with blue collar workers against students he called 'bums'."

Fifty years later, Chris McGreal at The Guardian writes that "the Kent State massacre marked the start of America's polarization."