We preach democracy while supporting dictatorships.
Those who don't remember the past are condemned to repeat the eleventh grade.
What gets lost in the textbook is the overall narrative. It gets lost in all the boxes and all the photos and all the little stuff that's stuck in all the time.
Conclusions are not always pleasant.
Students will start finding history interesting when their teachers and textbooks stop lying to them.
Textbooks should show that neither morality nor immorality can simply be conferred upon us by history. Merely being part of the United States, without regard to our own acts and ideas, does not make us moral or immoral beings. History is more complicated than that.