Any idea why and for what grade it is appropriate to teach Roll of Thunder, Hear My Cry?

I taught Roll of Thunder, Hear My Cry
to seventh graders, including several groups of, shall we say, reluctant
learners (summer school) with great success.  Having taught American history for quite
some time, I was able to make many connections to what was happening in the United
States during the time Taylor set her novel, and we also looked at how Taylor's own life
was reflected in the story.  In terms of literary elements, we looked at plot,
characterization, the usual stuff, and always spent some time with figurative language
because Taylor used it so masterfully in her descriptions.  The thing that most engaged
the students, however, was the institutional racism of Depression era Mississippi; they
were always horrified as the novel progressed, that people like the Wallaces were never
held accountable for their actions.  It opened up some great class discussions about
tolerance, and in terms of literary analysis, I think it was perfectly appropriate for
7th grade.