History of California-7

The 1960's was a time of upheaval and change in California, as well as the rest of the nation. One of the main  issues of the times was the Vietnam War. Many marched for peace, while many California bands made fantastic protest songs. However, much of the 60's was marred by violence. This was epitomized by the December 1969 Altamont Speedway Free Festival, where four people died, one of them stabbed to death by the Hells Angels, who were somehow hired to provide security. By this time, the hippy movement was fraying for a variety of reasons, so it was not this incident alone, but between the concert and the Manson murders, people saw a deeper significance to it.  

Watch the attached video. 

How did the Altamont Speedway concert, in a way, symbolically represent the end of the 1960's?

At least 600 words.