I'm a little torn over this one - on a personal level, I only liked it. I think it really suffered in comparison to the Octavian Nothing books, which are set at the same time and deal with issues of slavery and freedom within the context of the American Revolution - plus both books really emphasize the uncertainty of the outcome of the war, and the question of which side would do more for the abolition of slavery. Chains is complex and fraught enough for a middle school audience, while Octavian is a challenging read better suited to high schoolers and adults. There were several times in Chains when I found myself wishing for the period language of Octavian and its broader scope - but you know, Chains just isn't trying to be that kind of book, and I have to stop judging it in comparison. Laurie Halse Anderson is not trying to do what M.T. Anderson did.
When I try my hardest to judge Chains by its own merits, I see a book that I would have found gripping and compelling when I was in middle school. For kids who lap up historical fiction, this is great food, with a good balance between a reasonably accessible character and historical details. There are a few details about Isabel that I wondered about - like her ability to puzzle through Thomas Paine's Common Sense - but in the grand tradition of hooking readers into historical fiction, she's an outsider just like the reader, since she grew up a country girl and is moved to New York at the beginning of the book. There is some violence, but a lot of what Isabel suffers as a slave is fear - of being separated from her sister, of what might happen if she is discovered helping rebel soldiers. I'm curious to see what direction the story takes in the next book - but I never really got attached to Isabel, and I would recommend this book more for the topic and period it covers rather than any personal liking.