"Gatsby represents the American dream of self-made wealth and happiness, the spirit of youth and resourcefulness, and the ability to make something of one's self despite one's origins"
The American Dream is a vision that a man like Jay Gatsby has had, his parents were humble farmers, poor. He, now living in a rich, opulent house with a lavish lifestyle full of parties and fancy possessions, has achieved what can be described as the American dream.
The ability to rise from humble roots, in a country where opportunity for success is offered to anyone who is willing to work hard, and succeed beyond what his parents achieved in their lifetimes. To own a home, to be financially comfortable, to have stability in your work life, to be able to enjoy the fruits of your labor.
Jay Gatsby perceived from his humble job as a janitor, while working through school, that he wanted more out of life. He did not let his current position limit him, he strove for something better that is how he is the embodiment of the American Dream.