What is the function of setting in Death of a Salesman?

Consider the play is set in the late 1940's. Women were homemakers and men were the wage earners. Economic prosperity was in reach for many; the "American dream" (illusion or not) was expected by fathers and husbands. These economic expectations are what is expected of men like Willey. When they can't deliver, their manhood and very identity is at stake. Of course there is more to this from your question, but this is a start.