The early 1970s were the height of the hippy movement in the USA. The period was marked by social unrest around a number of social issues (the Vietnam war, racism, poverty, organised crime) and the hopeless optimism inspired by 'loved up' psychedelia (although the darker side of the drug experience was being documented by The Velvet Underground, and there were links between the drugs and the organised crime).
The society in which this social flux was ocurring was sharply differentiated on racial lines. There were seperate media serving the cultural needs of white, black and hispanic communities. In the urban African-American communities were on average, extremely poor, while experiencing the formation of a middle class. Thus they provided both source material and a marketing opportunity for a new film genre blaxploitation.
Please note that I managed not to drape a naked Pam Grier across the journal.