Because chief justice Marshall declared that slaves were not people, but we're property and there for had no right to sue in any way shape or form. This called for the fugitive slave act, which out raged abolitionist.
Military conquests by the Arab Empire and traders of Islamic faith were the primary means for spreading Islam to Africa, Europe, and Asia. I think its this one
It was the China civilization that did not get any achievements for all there work and achievements
