Before the Industrial Revolution slavery had been used already around the world in places like Egypt but it wasn't until the Industrial Revolution that the slaves when then traded across continents. The first slaves were used by Christopher Columbus to work on his ship but later on got used by the spanish and british in South America. In the Early years when America or "The New World" as they called it was found the Native Americans which were already living there at the time untouched by the rest of civilisation started to get killed or were taken in as slaves by the spanish. Spain used these slaves to build what they called the Empire of New Spain they started down at the bottom of America but started to move North. Most of these slaves were forced to work in the goldmines and were working 18 hours a day and six days in a week in terrible conditions and thousands of them starved to death or got worked so hard that they later died and because of this the spanish need to find someone else to fill to spots of the dead slaves so they turned to Africa and because they had already been visited by Europeans previously had grown resistant to some of the Europeans diseases and so were then taken as slaves. The early Europeans also raided the cost of Africa and kidnapped people that were able to work well for them of which they would then trade and sell.