James Baldwin was born to an unwed mother in Harlem, New York, and was the first of her nine children. His mother married David Baldwin, and James was therefore the elder half-brother to his eight younger brothers and sisters. David Baldwin, a carpenter and lay preacher, desired to be a good father to James but the animosity and discomfort between them never lifted.
James had striking characteristics that made him all the more alienated in a world prejudiced against his racial background; he was an intellectual and he was unattractive (William Condon, Cyclopedia of World Authors). The isolation and estrangement that he felt at home and in society drove him to reading, then to writing. He realized the pen was his only escape from Harlem and the only means by which he'd be able to help his large family of half-brothers and -sisters.
James Baldwin consistently explores the themes of isolation, alienation and the escape from confining social realities. In "Sonny's Blues," Baldwin once again explores these themes. Sonny and his brother are both victims of alienation and isolation in the cultural context of their lives. Sonny and his brother take different avenues for escaping social realities.
In the end of "Sonny's Blues," Baldwin realizes another predominating theme in his writing, also based on his own experiences, that of the victory over social and human limitations, victory on a personal level. Part of Baldwin's message is embodied in the fact that Sonny's victory looks different from his brother's victory.