Slavery is as old as mankind but it took on a special and particularly ugly aspect between 1700 and 1860. During that time, slavery became synonymous with skin color in much of the world, especially South and North America. In the US, people of African descent had to prove they were not slaves. By the time the Trans-Atlantic slave trade was shut down, millions of people had been captured, enslaved, and shipped across the ocean to a life of slavery. At the same time, this horrific system enriched the people who controlled this trade. How did the system actually work and who benefitted from it?