Exploitation and despoliation of Africa didn't stop when the slave trade ended, and its consequences haven't ever stopped.

Thinking in terms of compensation in a legalistic sense, with payments to individual descendants and so forth isn't the way to look at it. The point is, we are as a society a lot wealthier what we would have been because of slavery and the rest; and the countries if Africa and elsewhere are a lot poorer than they would have been.

We owe it to ourselves to do what we can to make good the damage and restore the balance.

Once again, it's not the suffering imposed then that should be the issue - it's the consequences of that suffering which continue to this day, in the form of poverty, wealth and inequality.

Yes, and there are past events in our own countries that impose the same kind of moral logic. For example there is a particular debt owed to mining communities which have lost their reason to exist, so that whole populations are stranded in wastelands.