Becoming a literary classic can spell death to one's street cred. For the last three decades of his life, Ralph Ellison spent a lot of time defending Invisible Man from a younger generation of black radicals, and defending himself for not finishing a second novel. By the 1980s, Invisible Man's subversively democratic last line—"Who knows but that, on the lower frequencies, I speak for you?"—spoke mainly to students in college classrooms. Lawrence Jackson's new biography, Ralph Ellison: Emergence of Genius avoids academic overgrowth by focusing on Ellison's early life and work, following the author through Invisible Man's 1952 publication and...