How long could the Atlantic slave trade continue for?

[eDGT]

I ran out of space for the proper title, but this is under a hypothetical scenario where Britain retains the Thirteen Colonies, either through representation in Parliament or offering them some sort of deal on increased autonomy, greater powers for state legislatures or something like that.

Anyway one of the reasons Britain- the leading power in the Atlantic Slave Trade in the late eighteenth century- would go on to ban slavery was due to losing their American colonies.  Their cash crop plantations of the Caribbean were never as extensive as those in North America, particularly in what we know as the South, and so once they were lost there wasn't much profit to be made from keeping it, and once the major player in the slave trade dropped out then most European nations had little reason to continue themselves.

That's very oversimplified I know but I'm just providing a brief context for the discussion.

So how long do you think the slave trade (and the institution of race based slavery) could have possibly continued for?

[steve59]

I don't know. The Caribbean plantations weren't as large as some of the American ones but they were still very rich and productive. I think the Americab plantations only became as important economically after the development of the cotton gin allowed much cheaper mass production of cotton to feed the growing textile factories and markets. This was weakened somewhat by the development of improved sugar beets during the Napoleonic wars.

Even so there would have been growing morale pressure as new ideas spread, opposing the slave trade and then the continuation of slavery after the trade was banned. Also don't forget there was also economic/political reasons to oppose slavery and hence the slave trade. Much of support for free soil arguments in the US was as much opposition to slave labour competiting with free labour as morally opposing slavery. While this is an argument against slavery the slave trade will be seen as an important factor in the larger institution.