What's the Value of a European's Skin Color in the Equator?

CNN's John Sutter looks at the history of slavery in early Europe. He says columbus was familiar with portugal and its slave trade, but he wasn't pro-slavery. Columbus believed that people near the equator had darker skin than those further north; they were also more likely to find gold on the far side of the ocean. This is valuable context for what comes next, Sutter writes.