Here is an article by Baldwin about Black English. Does his argument persuade you? Is it still relevant today? (Free registration required.)
Baldwin left the U.S. for a time in the middle of his life. This essay explores various expatriate writers who lived in Paris, including Baldwin
Baldwin had an FBI file due to his political activism, including his participation in the voter drive in Selma, Alabama in the early 1960s. This summary from the radio show Late Night Live describes Baldwin's encounters with the FBI.
To put Baldwin's life and work in historical context, consult this hyperlinked timeline of the Civil Rights Movement.