Re: slavery - Almost all societies/cultures had slavery. Many on a far greater scale than US. The US took around 400,000 slaves from africa in total while the arab world took 10 million. The reason there is a huge “african american” population and not a huge “african middle eastern” population of slave descendants is because the arabs castrated their 10 million slaves.

Additionally, while almost every culture/society had slavery, it was UK/christians who basically ended slavery globally.