The Atlantic Slave Trade

Write an essay discussing the causes, operations, and impact of the Atlantic slave trade, in African history.  When and why did the Atlantic slave trade begin?  What were the specific features of its operation?  In what specific ways did the Atlantic slave trade shape the development of African societies?  Some parts of your answer will touch on issues that are subjects of debate, and your essay should acknowledge the existence of those debates and explain some of the various viewpoints that exist concerning these issues.