Erica, nobody here DEFENDS slavery. It was not nice, but do you honestly think white Southern farmers, particularly poor ones (who were the vast majority) were treated nicely either by those in power? And do you have any clue what the Irish went through? The Chinese? Or, most of all, the Native Americans?
The instances of abuse/torture/murder of slaves were really quite rare. Most white Southerners would have rather been castrated than miscegenate, for instance, using the allegation of rape. Certainly they were treated better than their fellow African and Muslim overlords ruled over them in their native land.
And no, they did not ask to come to America, but I know for a fact that they had infinitely better lives as slaves to white Southerners than as slaves to other Africans.