One of the novel's considerable strengths is that it depicts the 1920s in the most stark terms. From a historical recreation, there is much in the novel that is reflective of the 1920s. Gatsby's parties are historical recreations of the affairs and celebrations that were so distinctive of the 1920s. Gatsby's chosen "profession" of a bootlegger is historically representative of the Prohibition lifestyle that was such a part of the time period, where being "bad" was considered "cool." Finally, I think that the freedom aspect that underscored so much of the characters' actions in the novel is reflective of the time period. There was no real sense of structure or control to how people lived, spent, or invested their energies. People of the 1920s used their freedom in a limitless capacity. People spent money extravagantly, like Gatsby. They flouted social conventions and defined their own being as they appropriated reality in accordance to their own subjectivity, like Tom and Daisy. They felt that there was no moral or ethical structure which had to be followed, like Jordan. In these elements, Fitzgerald's novel captures much of the time period in which it is set.
From a thematic point of view, a good argument can be made that Fitzgerald was quite prophetic about the frailties of the 1920s. The excessive pursuit of the American Dream that Gatsby comes to embody is representative of how so many in the 1920s excessively spent to pursue a dream of external happiness. The opulence intrinsic to the Jazz Age was predicated upon unlimited greed, purchasing stocks on margin or money that did not exist, and being able to acquire more and more. Gatsby spends this on a pursuit of Daisy, while others in the time period did so to equally satiate their own sense of acquisition. The hollowness that results from this helps to fuel the 1929 Stock Market Crash, something that Fitzgerald understood about the 1920s. Another element that is captured about the time period is the clash of cultures. Fitzgerald recognized that the stereotypical notion of parties, celebrations, and a festival- like approach to life existed in the realm of the rich. For those who lived like George Wilson, life was not a party. When Klipspringer sings his song about how the poor get mistreated while the rich party away, it is a telling condition of the cultural clash that was so much a part of the time period. For those like George Wilson, who were economically challenged, or those from the Midwest who were unaccustomed to the lack of moral guidance and structure that was such a part of the "Roaring '20s," there was a cultural collision of values that was an embedded part of the time period. This element is something that Fitzgerald recognizes and his detailing of it works on both a literary and historical level.