I'm from the states but I usually use peoples names no matter their skin color. What do you do go around calling people black or brown? yea that isn't offensive at all.

First of all you must be out of touch with modern terminology but negro is quite an offensive term. The term that is used is black which encompasses all children of the diaspora.
I suggest re-editing your post title.

Secondly your question does not make sense. What do you mean by releasing slaves?
Are you referring to freeing necks? Are we talking about present day America? How is that applicable?
If you are referring to the present America, unless you are referring to the prison system I do not understand your question.

Finally, Israelites were and are still for the most part black.

Negro is not offensive its Portuguese for the color black