"In the 3¼ centuries between 1492 and about 1820, four enslaved Africans left the Old World for every European. During those years, Africans comprised the largest forced oceanic migration in the history of the world. Who were they? Who organized the slaving voyages? Which parts of Africa did they come from? How did they reach the Americas? And where exactly did they go?"
The Society for Historians of American Foreign Relations has a variety of resources available for teachers on its website, including syllabi, primary sources, and assignments.
This source has a ton of resources, primary resources and secondary resources on the Great Migration. I want to have this on hand for when I need to teach this someday.