If you are overemphasizing the vicitmization aspects of slavery I cna see
why that would be uncomfortable for your students.  We as African
Americans get an overdose of that.  But if you also include discussion
about the resiliencey of our culture through our arts traditions, food and
families, there may be an opportunity for you to empower them with this
knowledge.  make the link between Negro Spirituals, the oral tradition and
rap.  talk about the significance of dance and trace the history from
traditional African dance to the cakewalk to hip hop moves.  There  are
tons of links, you just have to make it empowering and relevant.

just some ideas

Shana