In all cases, the reason was simple: slaves were, and are, a source of enormous profits (see: Thomas Jefferson).
"Colonies" replaced slavery during the 19th century. Fortunes were built on the back of slaves and on the work of colonies later. Some of which were slavery by any other name (See: Belgium, Leopold II).
The truth is, we need to stop and re-assess what we, Europeans, have done. For centuries.
If you disagree with this, please unfollow me and don't bother replying. OKTHXBYE. (2/2)