In Chapter 9 of The Great Gatsby, the American Dream is compared with Gatbsy's dream. What is your idea of what the promise of America is?
The promise of America is "equal opportunity". That is politico-speech describing a notion that suggests everyone in America will not be trapped and/or defined at birth as belonging permanently to a caste or class. Upward mobility is the term most often used to describe those who successfully exemplify the promise of America.
This is all rather stereotypical, I admit, but the promise is not especially well-defined in the founding documents of the USA. "All men are created equal" and "every man has a right to the pursuit of liberty and happiness" are phrases that help define the promise of America. These phrases paved the way for the Civil Rights movement and for social work beyond the Civil Rights movement.
They anchor the very idea of America, which is something bigger than representative democracy, something which acknowledges personal independence and which promotes the same.
To me the promise of America is the opportunity to achieve health, wealth and happiness. You are given the chance to live in a free society and make so many of your own choices that at least a fair portion of you life is in your own hands. This is one of the greatest countries in the world and so much is possible. In Fitzgerald's novel, his main character clearly has the potential to achieve my three nouns above and actually seems to for a short time, but the fact that he ultimately fails is part of Fitzgerald's theme about the failure of the dream.
To me, the promise of America is the promise of equality and freedom. America is supposed to be a place where your birth does not have that much of an impact on who you turn out to be. You can be born as Gatz, a relatively poor boy in the Midwest and become the rich Easterner Gatsby. You should not be looked down upon by anyone because of your birth.
This does not always happen, of course, but it is the promise of America.
You have made a shrewd observation concerning the link that Fitzgerald forges between the dream of Gatsby and the American Dream as a whole. You might benefit from moving this question to the discussion posting section of this group to gain a wider range of responses, however, let me start by sharing with you my ideas.
America is and always has been caught up with the idea of a fresh new start. Note how Fitzgerald refers to the "fresh, green breast of the new world" at the ending of the story. The first pilgrims that moved their considered it as a kind of Garden of Eden, where they could leave the corruption and decadence of Europe behind them and start afresh in a Promised Land. However, as the East became more and more settled, the focus of this new start was shifted to the concept of the Frontier, which was caught up with the endless ability to reconstruct yourself into whoever you want. The idea of the American Dream, which basically states you can achieve what you want if you work hard enough at it, is caught up with this concept of re-invention of self. Certainly, this is what Gatsby achieves in his dramatic transformation, and I think to a certain extent the same promise is open today. However, Fitzgerald points towards the way in which such "dreams" can own us rather than us owning them if we allow them to. Also, we need to be aware of the ways in which that American society is not a level playing field, and that certain groups of people have a significant disadvantage in trying to achieve their "American Dream" on the basis of their race, for example.