Why do athiest say sIavery is wrong?

The bible talks about slavery like that? Wow, now I hate it even more. People aren't property, they are people. It isn't made right because a book says it's okay. Also, not only atheists say slavery is wrong. Most sane people think so. And that last one, woman aren't freed like men are? Dang, that god of yours is a total ist. No offense to anyone, of course. =)