Slave trade and trade winds

In the 17th and 18th centuries, 12 to 15 million West Africans were forcibly transported by sailing ship across the Atlantic to the Americas, to work as slaves. These profitable voyages formed one leg of a three-stage journey, in the path of the south-east Trade winds. The other two stages involved the carriage of raw cotton etc from the Americas to England, in the westerly wind belt, and then manufactured goods south to Africa. Each stage took advantage of the prevailing winds, as can be seen from Fig 12.1. Essentially, the clockwise route went around the Azores (or Bermuda) high in the north Atlantic.