All too often, the story of slavery seems to start with the Civil War or slaves' attempts at escape. I know that many of my students were very surprised by the exhibits on the slave ships. Cottman's book addresses the fact that people were taken from their communities in Africa and sent as slaves to a number of places in a way that is not overly graphic but that does delineate just how inhuman this action was. This strikes a good balance for a book that might well introduce this atrocious chapter in history to children.
There are some color photos in the center of the book. While these pictures are illustrative, it would have been nice to see them included with the appropriate text instead of gathered in one place. I was a bit surprised at this; National Geographic has produced some beautiful and enticing nonfiction books with many more pictures that are more graphically pleasing. I know that cost is an issue in these, but using more pictures does make books more appealing to young readers.
Shackles from the Deep is an essential purchase for middle school and high school libraries, since it covers a variety of topics that are often studied, and is an excellent choice for readers who like converstaional nonfiction and are interested in history, civil rights, or maritime matters.