Watch out Jane Austen, you're not the only author 'round here who's interested in exploring prejudice. At its heart, Countee Cullen's short poem is a treatment of one of the most ubiquitous forms of prejudice: the racial kind. And it explores the problem of racism in an incredibly succinct way (remember, folks, this powerful poem has only 12 lines). Cullen's "Incident" meditates on how prejudice operates in America, how it affects our speaker's sense of self, and how it can ruin even the most gleeful of days in one single moment—or, as the case may be, in one single incident.
Straight up: "Incident" is a condemnation of racist culture in America.
Actually, it's more complex than that. "Incident" does not condemn the young Baltimorean. As a little boy, he couldn't possibly understand the power of the word "nigger."
One of the themes of "Incident" is the power of language. And no, we're not talking about the power of Hamlet, or the power of the Gettysburg address (though both are stuffed with super-powerful words). We're talking about the power of a single word. And as you know from reading the poem, that word is "nigger." It's a word with a long, complicated, and frankly terrifying history, and it's always been a form of hate speech. "Incident" dramatizes the power of this one short word as it tells the speaker's tale. There are few words in the English language with such a loaded history of pain, prejudice, hate, and enslavement. "Incident" amazingly captures all this history in just 12 short lines.
Zip it. We should never use the word "nigger" in speech—it's too offensive even to refer to in the context of the poem.
It's important to use the word "nigger" when discussing the poem; "Incident" is all about the power of the actual word. By discussing it openly, we're able to better appreciate its harmful power and so avoid it in future.
"Incident" isn't super-explicit about its coming of age theme, but it's there nonetheless. The incident that the poem describes is a moment of shock, but it's also a moment in which the speaker understands something new (and awful) about the world, and his place in it. It's a major bummer to think that this moment of coming of age comes about not because of an awesome achievement or a happy experience for the speaker (like winning a spelling bee or having his first kiss), but because of a disgusting moment of racial prejudice. Blech. But such was the reality for many African Americans in the beginning of the 20th century, and unfortunately, the reality for many racial minorities even still today.
As painful as it is, the speaker learns a valuable lesson in this poem. Namely: prejudice is real, and people can be just the worst.
The speaker would have been much better off not knowing about jerkfaces like the Baltimorean until he became old enough to deal with the grim reality of racism.