Thank you for posting this-I was planning on doing a lesson for Black History Month after my vacation ended. I teach at a grade school and my kids often laugh when they see people of color and say things like, "dirty!"
I'm a mixed race American who identifies as Asian-American, and they've still got trouble wrapping their heads around the "American" part. To their minds, Americans are blonde, blue-eyed and, to quote my students, "FAT!" I've also been asked by co-teachers if I want to be a "real American".
So I think it's fantastic you've made a powerpoint that shows how Blacks in America have helped contribute to history. I'll custom edit this for my class and give them a little taste of cultural diversity! :D