What happened next
Although the British ended their slave trade in 1807, slavery itself continued in the British colonies until full emancipation in 1833. An illicit slave trade continued across the Atlantic, and more than a million Africans were landed in the Americas (mainly Cuba and Brazil) after 1807.
Historians remain puzzled by the abolition of the slave trade. Was it ended because it was no longer profitable? The economic data, and the tenacious support of the slave traders, suggest not. But is it plausible to see abolition being brought about by outraged sensibility or religious sentiment? If it was wrong or un-Christian in 1807, why not in 1707?
What exactly changed in Britain and the Atlantic world - and indeed in Parliament - in the years between 1600 and 1807? There seems to have been a shifting of the tectonic plates; a small series of movements which produced massive consequences.