Escape from Slavery: Five Journeys to Freedom
Used in a classroom setting, I can see that each story would be sure to spark intense interest. But this isn't just a classroom book -- any child with an interest in history or a penchant for suspense will find this an interesting book.
The first tale is a short one of a slave escaping across a frozen river with her young child. It's a good strong start, but my personal favorite is the last story Two Tickets for Mr. Johnson and Slave about the daring escape of a husband and wife under the very noses of the people who would oppress them.
I recommend this book for ages 8-12, girls or boys. Teachers should definitely take a look at this one as well -- it would be hard to find a book better suited for classroom use.