While characters such as Willy, Linda, and Happy believe the U.S. to be a wellspring of easy opportunity and imminent success, the 1940s America of Death of a Salesman is crowded, competitive and mundane. This contrast sets up an important gap between reality and characters’ aspirations in the play. In the end, Willy’s belief that his self-worth is determined by material success destroys him.
By directly linking his sense of self-worth to the achievement of the American Dream, Willy’s professional failure becomes personal failure and a crisis of identity.
Biff’s struggle in Death of a Salesman is primarily one of separating his sense of self-worth from his professional life.