This is a 48 page non-fiction book (AR level 5.7, .5 points) about the history of the Transcontinental Railroad across the US.  The information is presented in a clearly-written manner with a format full of actual photographs and illustrations depicting the subject.  The books in this series are very approachable for kids and even the cover art entices the reader to pick it up and check it out.  The prices is reasonable as well for a hardcover book.