What is the historical importance of the novel Deliverance?

Although it's a relatively simple straightforward story, Deliverance is in many ways a continuation of very old American anxieties and a reflection of the era in which it was written. Since the rapid expansion of territory and increased use of technology that began in the 19th century, many Americans have felt a sense of over-civilization, feeling that all the modern convenience has disconnected them from the natural world and a kind of pioneering spirit that contributed to the development of the United States. This perspective is espoused by Lewis, who has organized the trip as a way to get back to nature and celebrate their masculinity.

Not long after beginning their trip, the group starts to recognize that the reality doesn't quite match Lewis' primitivist fantasy. Not only do they lack the skills to navigate what they come to recognize as an isolated and rugged terrain, but they are also eventually attacked by locals, which dramatically changes the group dynamic and gives things a much more serious and dangerous tone as they fight for their lives trying to get to safety.

Written in 1970, Deliverance was published during a time of considerable social unrest in the US. Not only was the country involved in an increasingly divisive war, but it was also undergoing significant cultural transformation. This is the era of civil rights when African-Americans, the LGBT community, and feminism were pushing hard to change the social hierarchy that placed a very high value on straight white men. The influence of these movements is reflected in the character of Lewis, who is hypermasculine and somewhat resentful of the others for not being as adventurous (masculine).

Although there are other books released around that time that are probably more historically significant, many are written from the perspective of the marginalized or oppressed. Deliverance, on the other hand, reflects the ways that modernity, feminism, and the changing social structure of the United States affected many men, particularly the feelings of loss and disconnection that many felt.