Writer Sarah Vowell and her twin sister re-trace the “Trail of Tears” — the route their Cherokee ancestors took when expelled from their own land by President Andrew Jackson. On the way, Sarah and her sister visit the land they would have grown up in had the Cherokees not been expelled, Andrew Jackson’s home, and the land in Oklahoma where the Cherokee nation settled (and where Sarah and her sister were born). They reflect on their own American-ness and Cherokee-ness, and on the more difficult question: What’s history good for, anyway?