Throughout the course of the novel, our nameless narrator is mistaken for a reverend, a pimp, a gambler, a fink, a unionist, a Southern Negro, a New York Negro, a rapist, a lover, a doctor, and a good singer. That's not to mention the three names he goes by: his own (which we never learn), the one the Brotherhood gives him (which we never learn), and a man named Rinehart (who is responsible for at least the gambler/reverend/pimp combination). All this raises the question… who is he really?
Great question. The thing is, the narrator doesn't know either, because for the longest time his identity has been dictated by white-dominated society. First he tried a humble "I'm a Negro who knows my place" attitude, which got him expelled from his college. Once in Harlem, he joins an organization called the Brotherhood, which is all for racial integration, but ultimately much too far removed from the actual realities of being black in America. It turns out the Brotherhood was using the narrator as a token black man, or a way of saying, "Hey, look! We like racial equality!"
Ellison writes in his introduction that one of the problems with most literary portrayals of blacks in his time was "the question of why most protagonists of Afro-American fiction (not to mention the black characters in fiction written by whites) were without intellectual depth. Too often they were figures caught up in the most intense forms of social struggle, subject to the most extreme forms of the human predicament but yet seldom able to articulate the issues which tortured them." Invisible Man is Ellison's attempt to fill that gap. More than anything else, the story's narrator is thoughtful and articulate about his experiences, which lead him into a space (both literal and metaphorical!) where he rejects society's constant attempts to label or emblematize him.
So, the narrator goes underground to "find himself." Of course, this begs the question(s): By the end of the novel, has he found himself? Why is he ready to return to society? Ball's in your court.