Slavery was wrong no matter who was doing it. What is the name of the lady who you say owned most of the slaves in the country? And was she BLACK or was she mostly white as most 'free people of color' were? It's a stupid booklet and I won't defend it just because the schools may not be PC.
Ah, yes. But why is/was it wrong?
(HINT: Slavery first became wrong in cultures where the right(s) to private property were not only acknowledged but enforced by the law of the land.)
This school apparently wants to offer facts and alternate viewpoints. In this manner they will let the kids form their own opinions.