How was the relationship between Willy Loman and his sons, and how Wily influenced their lives?

Biff is Willy's eldest son; once a high school football idol, he has grown into a man who, in his mid-thirties, displays only a small measure of his youthful confidence, enthusiasm, and affection, and more often appears as a troubled, frustrated, deeply sad man with a tendency to escape into dreams at times. Biff was betrayed by his father at a very young age when he discovered that Willy was having an affair. Biff, who steals things as an adult, blames his father for not giving him the proper guidance when he was caught stealing as a child. Biff also blames his father for instilling in him the belief that success lies in the accumulation of wealth; it is because his father programmed him to think this way, Biff believes, that he is so unhappy and cannot enjoy doing the outdoor labor for which he has a talent. Biff is tortured by his disillusionment with Willy, by his failure to live up to his own standards, by his failure to achieve the greatness that Willy dreamed he would, by his desire to get back at his father for what he believes has been done to him, and by his great love for Willy, which creates in him tremendous confusion and emotional turmoil.

Happy is the younger of Willy's two sons; he has grown up in the shadow of his older brother, and consequently has a hard edge to his personality that the other characters lack. He appears more content than Biff, but at the play's end he is drawn into his father's illusion; he pledges to take up his father's cause and succeed where his father had failed.