What is F. Scott Fitzgerald's view of the American Dream and why did he say it was dead?

In The Great Gatsby, Fitzgerald uses a variety of literary devices to portray the American Dream. One example is the the green light that symbolizes Gatsby’s hopes and dreams for a life with Daisy. Another symbol is the Valley of the Ashes, which represents the ugly consequences of America’s obsession with wealth. Fitzgerald uses these symbols to convey the illusory nature of the American Dream.