All the inaccuracies & omissions Loewen discusses are backed by primary sources & fully documented (it's nice to be able to verify the lies the textbook-industrial complex has raised you on), and he invites you to delve deeper & do your own research if you feel disinclined to take him & his sources at their word. In addition to plain old getting the facts wrong, Loewen discusses the general narratives (sketchy at best, flat-out offensive at worst) to which textbook authors seem to be committed, and how the errors and omissions are carefully selected to prop them up. He also demonstrates how the tone of history textbooks tends to be authoritative and objective, completely understood and agreed-upon and ready for students to memorize, rather than full of controversies and open questions that they might explore and draw conclusions from on their own.
So yes. If you feel like your education in US history was a-okay, I invite you to take a read. It will likely change your outlook not only on the past but on the present & future as well.