what is the right way to teach slavery to yung student (elementary) ? How about older students (high school)

I really personally dont think it should be taught in school at all, honestly I do not like history at all, due to what both men and women dealt with, from the unequal rights to the other horrible things that occurred. It seems like disrespectful to teach this due to it being some of their ancestors that were slaves at a time or any part of history in that matter. I think if a student wanted to learn about it then they should read about it in the libraires, or ask a teacher for tutoring on the subject, and not actually teach any students about this.