African Kings and slave traders used their guns (that they got from the European) and shackles to capture their neighbors. This caused major disharmony between tribes as money became more important than trust and friendship.
Captured Africans would taken to the holding places along the coast. Some would have to stay there for 3 months waiting for the ship. Here, many would get sick from diseases and die from malnutrition. Also, the prisoners here were all from different tribes, so couldn't all speak the same languages.
The prisoners were 'tightly-packed' on the ships, causing diseases to spread very fast. Since the African slave traders captured well, young and fit men, that meant there were less young men working. This caused Africa's economy to shrink and become unstable.
Slaves were owned as if they property by the Americans and Europeans. They would work all day, everyday for them. They didn't have a proper shelter to live under.
WORK WORK WORK!
Years after the slave trade was abolished, racism as still an issue. People still didn't see black people as people. They were seen as inferior beings who were not allowed to mix with the others, eg. toilets.
Today, many Africans from all over the world (descendants of the slaves) have lost their culture, language and traditions due to the slave trading