The Jim Crow era directly followed the Reconstruction period in the United States history. The name Jim Crow comes from a white actor who portrayed a dim witted black slave in the 1830's. Jim Crow is used to describe segregation laws, customs, etc.
Significant conversions also occurred beyond the extents of the empire such as that of the Turkic tribes in Central Asia and peoples living in regions south of the Sahara in Africathrough contact with Muslim traders active in the area and Sufi orders.