I totally get why this book (author Mildred Taylor) won a Newbery in its year of publication. Set in the 1930's, it is the story of a black family living deep in the heart of Mississippi who is dealing with the ugly reality of racism at its worst. The Logans are a rarity because they own their own land (400 acres, to be exact), and are therefore exempt from lots of the difficulties that sharecropping black families deal with. However, because of their position of independence, they are somewhat of a target for the hate-filled racists who are looking to keep the "coloreds" in their place.
As I read it, I thought about lots of different angles from which to go about teaching this book in depth to students. The themes of friendship, trust, character, strength, responsibility, conformity vs. nonconformity, etc. would make this book an excellent choice for classroom study or a student book club. Just know that it is a question-sparker for sure...those make the greatest books! By the way, Thunder was written on an upper 5th grade reading level.
Curiously enough, David Logan (Papa) reminded me soooo much of my beloved Atticus Finch (To Kill a Mockingbird). He is the one to calm his family with the "it's not time to worry yet" phrase, and he handles the drama with class and nobility.