Why was The Great Gatsby important during the Jazz Age? How was it influential and what is its meaning?

The Great Gatsby represented all the excesses and exuberances of the Jazz Age, the time between the end of World War I and the stock market crash in 1929 that led to the Great Depression. The novel reflects the spirit and the texture of life in that period. As readers, we witness the sense of optimism, consumerism and good times that characterize the Jazz Age, primarily through Gatsby's wild parties. The parties show the period's rebellion against Prohibition: in this novel, the booze runs freely, and Gatsby builds his fortune, in part, on bootlegging. The novel also depicts the new sexual freedom of the age, as well as the New Woman, represented most fully by Jordan Baker, an athletic golfer with short hair (a new and daring style for women in the 1920s) and the freedom to come and go as she pleases.

For the first time, millions of Americans owned cars, and cars become an integral part of Gatsby's story, carrying legions of guests to Gatsby's parties on the edge of Long Island, causing Myrtle Wilson and Tom Buchanan to meet through her husband's gas station, carrying our main characters to New York City and finally, creating tragedy. 

The Great Gatsby became most influential during (and after) World II, when the army gave out copies to the troops. The book did not sell as well as expected when first published, but two decades later came to represent a lost and hopeful period of American life.

The book captures the flavor of the Jazz Age like no other, by one who lived through it and was one of its chief representatives. Fitzgerald and his wife Zelda, young, beautiful, partying and audacious, were the face of a new age that rejected Victorian repression--and this novel also became its face.

However, the novel's meaning is more complex. While writing it in 1925, Fitzgerald couldn't have foreseen the stock market crash that ended the decade-long party, but he did show the undercurrents of careless and excess that, in the end, would undo the economy. Beneath the celebration, the book is a somber look at the problems caused when we base our lives on illusions, in the champagne bubble of a dream.