The original title of this play was 'Inside a Man's Head,' a much more leading title as to theme than the final product. Willy and Linda are content in their lives and their marriage; their one overwhelming desire and focus is to own their own home by paying off their mortgage. Ownership, a huge part of the American dream.
Willy Loman's character is broken by an unfeeling profession. It's often thought that what seems to be Miller's criticism of the American Dream stems from his socialist views. Willy believes that success hinges on a charismatic personality, that if you're popular and well liked, you can attain anything you wish. This is his preferred work ethic and the one he passes down to his children.
Willy's parental teachings don't pan out the way he'd believed. His son grows up to be a drifter, and he himself is fired from his job because his performance in no way lives up to his perceived ability to charm.
In the end, we see Willy working around the house, building a garage, using his hands and being happy. His American Dream became nothing more than a nightmare, and the things that made him happy were really the dream.
Source(s): Death of a Salesman