“...slavery hung on a lot longer, to this day in some cases, in Muslim, Middle Eastern and Far Eastern areas”
I thought that’w what I said.
Colonial powers in the 19th century abolished slavery in the areas under their control.
Slavery lingered the longest not in colonized areas but in independent nations and tribal areas.
IOW, the expansion of colonization in the middle and late 19th century meant the gradual end of slavery, not its expansion or toleration.