Explore both ideas. For your Freestyle Brainstorm day coming up, just write write write all the ideas that come to you.

Also, remember that this is fiction. Revolution is possible. You just have to pace your story accordingly... meaning faster paced action for larger scope. We may be living in a political climate in which readers will empathize with the Cherokee in your story and even find it believable if your reservation wins its revolution and becomes its own sovereign nation with its own flag and Olympic bobsledding team and everything.

Smaller scope is easier to pin down, though, you're right. Justice for the chief's murder is a compelling story, too.

Just be sure you have a main character, that the character has a clearly defined goal we all want to see him achieve, and that there are significant hurdles in his way.

Cheers,
Michelle