Quite true, Svetlana. This was explained briefly in King Leopold’s Ghost, particularly a man by the name of Morrell in England, who spent his career trying to stop the horrendous treatment of blacks in the Belgian Congo. On his many trips to raise funds in the United States, he met and became friends with Samuel Clemens (Mark Twain), also an early abolitionist. One point often overlooked is the fact that slavery is thousands of years old. Even American Indian tribes had slaves. Cervantes was a slave. Another interesting fact: European slave traders didn’t invade tribal villages with guns and chains. The trading itself was done by Arabs who dealt in many items, including slaves. Tribal leaders were, in fact, the ones who decided who would be slaves. Very often, they chose those who represented a threat to their authority and position. They got rid of their rivals and troublemakers.