Answer: Well...I think this will help.
Slavery was common when Hazrat Muhammad (SAW) started preaching Islam. As Islam teaches equality of all human beings, the early converters to Islam were mostly the slaves and the poor. Islam does not like slavery.
But it was not possible in that society to announce it Haram. However, the Holy Prophet (SAW) commanded the Muslims to treat the slaves kindly, give them the same food which the master eats, don't be cruel to them, preferably set them free. Hazrat Zaid (rau) was a slave set free by Hazrat Muhammad (SAW). Hazrat Bilal (RAU) was also a slave bought and set free by Hazrat Abu Bakr (RAU). Both of them enjoyed more respect than many of the other Companions (RAU).
Explanation:
Imperialist powers did not seek cotton in Southeast Asia.
Usally, by horse. (unless you are speaking of what route the would take to get places.)
