[T]he generation of the Founding Fathers, who certainly knew the story of Noah and his sons, nonetheless believed in the equality of the races. - Harry V. Jaffa

Don't we hear nowadays objections on the part of the labor unions to importing goods from China, which are made with slave labor? Is the existence of slave labor not a reflection upon the idea of a free commercial society?

Slavery in the British colonies of North America was more than a century-and-a-half old before independence. It was roundly condemned, at one time or another, by nearly all the important political personages of the Revolution. I know of no instance in which any of these personages contradicted the doctrine of the Declaration, or maintained that slavery was a positive good. We must recognize, however, that slavery next to the family was perhaps the oldest institution of civilized mankind. Its origin in the ancient world came with the discovery that it was more profitable to enslave an enemy defeated in war than to kill him. The ancient law of the ancient city may be seen in the Bible. When the Israelites conquered Jericho, they put to the sword everyone in the city—men and women, young and old, sheep, oxen, and asses. Only Rahab the harlot and her family were spared, since they had given shelter to the Israelite spies. Later, in the custom of ancient warfare, the males of a defeated people would all be killed, but the women and children would be carried into slavery. Eventually the entire population of a defeated people would be enslaved. Such are the steps in the human story. That defeat in war meant slavery was the rule for many thousands of years.

Diversity in the service of freedom might be a very good thing. Diversity in the service of slavery might be a very bad thing.