Ronald

the 68 protests in chicago were around the democrat national convention and the vietnam war.  basically it was a HUGE protest outside the democrat convention (where they were going to officially anounce the presidential candidate) that was completely covered by the news.  people watched live on their tvs young americans being abused by the police.  the mayor of chicago had refused them a license to protest and the police were really brutal.  this is when the vietnam protests really became huge and it changed everything in the US as parents and adults were astonished that the police would do this to their sons and daughters.  really (side note) the main reason protests became big that year was the draft was opened up to university students.  so it was the university students that were able to dodge the draft before that were outraged because they were educated and understood how unjust and ridiculous the war was.  
this was also the starting point of the chicago 7(or maybe it was 8).  They were a group of young protestors that really led the movement.  one of them famously wrote the book "steal this book"- abbie hoffman (he is also portrayed in forest gump as the guy at the washington dc protest leading the ralley in an american flag tshirt).
ps i know this because 1. i am american 2. my dad was one of those outraged college students protesting!