In 1727 Dahomey conquered the coastal kingdom of Hueda and took its port at Ouidah, and for the next century and a half the state's revenue rested heavily on selling captives to European traders there. The coast this stretch belonged to was called the Slave Coast, and the people carried from it, Fon, Yoruba, Ewe and others, went in very large numbers to Saint-Domingue, to Bahia and to Cuba.
What went with them was not only labour. The religious vocabulary of this region is the clearest single ancestor of the African American traditions of the Caribbean and Brazil: the word vodun itself, the figure of Legba at the crossroads, the serpent Dan who becomes Damballa, and the structure of initiation into the service of a particular spirit. Haitian Vodou, Cuban traditions and Brazilian Candomble each drew on it and on Yoruba practice, and each became a religion in its own right rather than a survival.
Dahomey resisted the French until 1894, when the last king was deposed and the kingdom annexed. The vodun did not end with it: Benin recognised Vodun as a national religion and instituted an annual national day for it in the 1990s, Ouidah holds the largest of its gatherings, and the port's memorial route to the shore is now a place of return for descendants of those who left from it. This is a living tradition with its own authorities, and it is described here rather than explained.