I have been consistently impressed with books in Scholastic’s True Book series, and this one is no exception.  The text is detailed enough to be truly engaging and informative, yet organized and clearly stated so as to be accessible to young readers.  Text is broken into reasonable chunks, in a large enough font so as not to be intimidating.  Diagrams and illustrations and photos support the text and catch readers’ attention/interest.  The graphics/layout support and attract without distracting.  My one gripe is one I’ve had with a lot of non-fiction books lately:  listing facts horizontally by date and calling it a time-line, even though nothing about the line represents the passage of time (everything is equally spaced, whether the events were separated by a year or three centuries).  All in all a solid choice.