What are the major themes in Lies My Teacher Told Me by James Loewen?I would like themes that are dug deeper than the fact that books are about...

The major theme in this book is not that history books
glorify America.  It is that history is taught (by teachers and by textbooks) in ways
that make history uninteresting to students.  Loewen argues that this is a major reason
why Americans have such a poor understanding of
history.

You are right to point out that one problem is
that the books glorify America.  However, this is not the major problem that Loewen
sees.  He thinks that history books concentrate too much on facts and figures and
obscure the important things about history.  They do not, he says, teach us about the
connections between the past and the present.  They do not focus on causes and effects. 
They tell us too much of what happened, but not enough
about why things
happened.

Loewen's main theme in this book is that the
textbooks used to teach American history are written in such a way as to make history
boring to the average student.