Historically, many slaves were not permitted or able to reproduce, this is one thing that distinguishes the slave trade in the United States. Trying to make amends for those slaves whose line ended with them is probably impossible.

On the other hand, a great many people today all around the world, and of many skin colours are descended from slaves. I am mostly familiar with this history in Europe and Africa, though I have no doubt it went on to a greater and lesser extent elsewhere. Supposing that the average reader here, who does not consider themselves to be "minority", is a "white" American, how confident are you that your ancestors do not include many slaves? Slavery in Europe still exists, but in the traditional sense with open buying and selling and large-scale enslavement it was openly and widely practiced in England and Germany and Poland and wherever you trace your ancestry no more than a thousand years ago.

You may consider it inappropriate to put a time limit on suffering, but in practice it's implicitly done all the time. The US is exceptional in having so many people who bear clear marks of historically nearby enslavement. Other parts of the world have been more successful in forgetting.

If I proposed to some Ivy League admissions panel that the descendants of biblical Jews should be favoured over those of Egyptians on account of enslavement would anyone listen?