This book could be used to teach Social Studies. Mostly on a unit dealing with exploration, but it may need to be read over many lessons depending on the grade level.
I've thought long and hard about how to train children to be responsible and good people, and even more than that, how to train them to be heroes. Outside of the scriptures I don't know that there is a better way to light the fire in people to become good and great than by reading biographies about good and great people. The Value of Series by Spencer Johnson is one biographical series written for children that I can't recommend highly enough. All my children grow up reading them. How I wish every child in the world had the same privilege.