The American Dream that anyone can achieve financial success and material comfort lies at the heart of Death of a Salesman. Various secondary characters achieve the Dream in different ways: Ben goes off into the wilderness of Alaska and Africa and lucks into wealth by discovering a diamond mine; Howard Wagner inherits his Dream through his father's company; while Bernard, who seemed a studious bore as a child, becomes a successful lawyer through hard work. Willy Loman's version of the Dream, which has been influenced by his brother Ben's success, is that any man who is manly, good looking, charismatic, and well-liked deserves success and will naturally achieve it.
Over the course of his lifetime, Willy and his sons fall short of the impossible standards of this dream. But the real tragedy of the play is not that Willy fails to achieve the financial success promised in his American dream, but rather that he buys into the dream so thoroughly that he ignores the tangible things around him, such as the love of his family, while pursuing the success he hopes will bring his family security. By sacrificing himself at the end of the play in order to get his family the money from his life insurance policy, Willy literally kills himself for money. In the process, he demonstrates that the American dream, while a powerful vehicle of aspiration, can also turn a human being into a product or commodity whose sole value is his financial worth.
The central conflict of the play is between Willy and his elder son Biff, who showed great promise as a young athlete and ladies' man, but in adulthood has become a thief and drifter with no clear direction. Willy's other son, Happy, while on a more secure career path, is superficial and seems to have no loyalty to anyone.
By delving into Willy's memories, the play is able to trace how the values Willy instilled in his sons—luck over hard work, likability over expertise—led them to disappoint both him and themselves as adults. The dream of grand, easy success that Willy passed on to his sons is both barren and overwhelming, and so Biff and Happy are aimless, producing nothing, and it is Willy who is still working, trying to plant seeds in the middle of the night, in order to give his family sustenance. Biff realizes, at the play's climax, that only by escaping from the dream that Willy has instilled in him will father and son be free to pursue fulfilling lives. Happy never realizes this, and at the end of the play he vows to continue in his father's footsteps, pursuing an American Dream that will leave him empty and alone.
The towering apartment buildings that surround Willy's house, which make it difficult for him to see the stars and block the sunlight that would allow him to grow a garden in his back yard, represent the artificial world of the city—with all its commercialism and superficiality—encroaching on his little spot of self-determination. He yearns to follow the rugged trail his brother Ben has blazed, by going into the wildernesses of Africa and Alaska in search of diamonds, or even building wooden flutes and selling them on the rural frontier of America as his father did. But Willy is both too timid and too late. He does not have the courage to head out into nature and try his fortune, and, anyway, that world of a wild frontier waiting to be explored no longer exists. Instead, the urban world has replaced the rural, and Willy chooses to throw his lot in with the world of sales, which does not involve making things but rather selling oneself.
Biff and Happy embody these two sides of Willy's personality: the individualist dreamer and the eager-to-please salesman. Biff works with his hands on farms, helping horses give birth, while Happy schemes within the stifling atmosphere of a department store. While Willy collects household appliances and cars, as the American Dream has taught him to do, these things do not ultimately leave him satisfied, and he thinks of his own death in terms of finally venturing into nature, the dark jungle that the limits of his life have never allowed him to enter.
Inspired by his love for his family, Willy ironically abandons them (just as he himself was abandoned by his father when he was three). The tragedy of Willy's death comes about because of his inability to distinguish between his value as an economic resource and his identity as a human being. The Woman, with whom Willy cheats on Linda, is able to feed Willy's salesman ego by "liking" him. He is proud of being able to sell himself to her, and this feeling turns to shame only when he sees that by giving stockings to The Woman rather than Linda, he is sabotaging his role as a provider. He doesn't see that his love, not material items, is the primary thing Linda needs from him.
The link between love and betrayal is present throughout the play: part of Biff's revelation at the play's end is that Willy has betrayed him by encouraging him to settle for nothing less than greatness, thus making the compromises of the real world impossibly difficult. Happy, and even Linda, also betray Willy out of a kind impulse to not shake him out of his illusions, which forces Willy's fragile mind to deal alone with the growing discrepancy between his dreams and his life.