Conversational, Urgent
Sometimes it's best to write in a conversational way, you know? Especially if the story you're writing comes from an oral tradition, as is the case with "The People Could Fly." It would be kind of weird to take a tale that's passed mouth to ear and then make it all formal on the page. But let's look at what this looks like in practice.
Hamilton frequently starts sentences with "they say" or "say" (1), implying that she's simply relaying a story that was told to her and fostering the sense that she's casually doing the same to readers. Similarly, the use of dialect (a.k.a. language that reflects where someone's from—think: hella, wicked, and so on) through words like "flyin" (3) and "outcryin" (27) adds to the sense that this story is meant to be spoken, rather than written. Which, again, it was.
In a similar fashion, Hamilton uses short, rapid-fire sentences to create urgency. Take a look at this passage, for example:
That whip was a slice-open cut of pain. So they did move faster. Had to. (6)
By using short, punchy sentences (and sometimes fragments), Hamilton mirrors the violence she is describing through her language. That first sentence above slices, there's nothing extra or flowery to it—it delivers pain swiftly. Sentences like these create a sense of forward momentum (and, at times dread), too, that keeps our eyes glued to the page until the story ends.