These papers explore the history of the tropical regions of the Atlantic basin, sometimes focused on the Caribbean, sometimes on Africa, but always with a comparative dimension. The Atlantic basin is central to most of these comparisons, but they are a part of an even broader effort to capture the perspective of world history. Some deal with the shores of the Atlantic in the framework of economic history, but the author's concern is most particularly with the role of the environment in history, especially the disease environment. Disease was particularly important for migrants who moved from one disease environment to another. In the tropical Atlantic, disease was a crucial factor in the formation of the slave trade, affecting both the involuntary passengers and those who came out from Europe to manage the trade.