The Handbook of Yoruba Religious Concepts by Baba Ifa Karade.
Excerpt from the back cover:
Most of the Africans who were enslaved and brought to the Americas were from the Yoruba nation of West Africa, an ancient and vast civilization. In the diaspora caused by the slave trade, the guiding concepts of the Yoruba spiritual tradition took root in Haiti, Puerto Rico, Cuba, Brazil, and the United States. In this accessible introduction to the Yoruba tradition, Baba Ifa Karade explores the spiritual source of the beliefs and practices and their profound influence in the West.