Describe the institution of slavery under islam

I had got this off a website but it was to small to see hope you do not mind I am copying and pasting but here you go

Islamic views on slavery represent a complex and multifaceted body of Islamic thought, with various Islamic groups or thinkers espousing views on the matter which have been radically different throughout history. Slavery was a mainstay of life in pre-Islamic Arabia and surrounding lands. It was in this social milieu that Islam emerged, whence the Quran and the hadith address slavery extensively, assuming its existence as part of society but viewing it as an exceptional condition and restricting

c. the passage of the fifteenth amendment