Slavery ever since yesterday until today
Slavery exists since the night of times, because peoples like to control and utilize the weakest. In Egypt and in Greece the slaves were batter enemy or bought barbarians. Slavery was a admit institution, often essential at the economy and the society, of all the antiques civilizations.
During the middle age with the appearance of the Christianity the condition of the slaves improved a little, but the slavery did not disappear for such.
Then peoples discover news countries think the navigation, and when they had massacred the native peoples they mattered like livestock African workforce. The slaves traversed Atlantic in horrifying conditions.
Fortunately in 1848 all these practices were abolished. But regrettably in certain countries slavery always exists under names different, such as: exploitation of the children or clandestine industry.