What part does social class play in the novel?

Class

Class is an unusual theme for an American novel. It is more common to find references to it in European, especially British novels. However, the societies of East and West Egg are deeply divided by the difference between the noveau riche and the older moneyed families. Gatsby is aware of the existence of a class structure in America, because a true meritocracy would put him in touch with some of the finest people, but, as things stand, he is held at arm's length. Gatsby tries desperately to fake status, even buying British shirts and claiming to have attended Oxford in an attempt to justify his position in society. Ultimately, however, it is a class gulf that seperates Gatsby and Daisy, and cements the latter in her relationship to her husbad, who is from the same class as she is.

For Chapter 6 in particular,

It is significant that Gatsby leaves college because he finds his work as a janitor degrading. This seems a perverse decision, given the fact that a university education would dramatically improve his social standing. His decision to leave reveals Gatsby's extreme sensitivity to class, and to the fact of his own poverty; from his childhood onward, he longs for wealth and­ for the sophistication and elegance which he imagines that wealth will lend him. His work as a janitor is a gross humiliation because it is at odds with his ideal of himself; to protect that ideal, he is willing to damage his actual circumstances.

Fitzgerald uses the character of Dan Cody to subtly suggest that the America of the 1920s is no longer a place where self-made men can thrive. Cody, like Gatsby, transcended early hardship to become a millionaire. Like Gatsby, he is remarkably generous to his friends and subordinates. Cody takes to drinking because, despite his wealth, he remains unable to carve out a place for himself in the world of 1920s America. It is important to note that Cody's death is brought about, at least in part, through the treachery of the woman he loves; this foreshadows the circumstances of Gatsby's death in Chapter VIII.