Crow is a singularly effective piece of historical fiction. It both captures and transcends the time and place it describes, and I think structure and pacing are key to its effectiveness.
It begins with a portent - "The buzzard knew." From there, though, it moves on to paint an episodic, leisurely portrait of a way of life that seems idyllic compared to what is to come. Moses's concerns, for the most part, are the concerns of any sixth grade boy: will he get a bicycle? Will he lose his best friend? Who's hiding the treasures near the swimming hole? As Wright takes her time setting the scene, the reader gets a vivid sense of place and of character.
Throughout the first half of the book, though, there is a trickle of race-related trouble - the slogan contest, the accidentally stolen bicycle - which gradually builds, becoming a deluge at the rally in Fayetteville. From there, the pace picks up and we are rushed from one horrific event to the next, culminating in the destruction of everything Moses and his family value. This second half would not be nearly as effective without the hopefulness of the beginning chapters, and the transition between the two is accomplished seamlessly.
I'm not sure where structure fits within the Newbery criteria, because I don't think it's plot, exactly. It's some gray area between plot and style, and possibly presentation of information. I do feel confident in saying, though, that Crow features distinguished characters and settings, and those are key to its emotional impact. The destruction of black Wilmington means something to us because Wright has shown us exactly what is being lost.
If I have a complaint about the book, it's that Moses's presence at every one of the historical events felt a bit forced - like a You Are There! tour of the Wilmington race riots. I think that's a common pitfall of historical fiction.
Sam liked a lot as well, and I'll be curious to hear how he thinks it compares to The Lions of Little Rock as a novel focused on race and civil rights.