It is also sometimes used to describe a number of folk-religions in [West Africa]?. Considering that the the majority of the Africans who were brought to Haiti and the southern US as slaves were from West Africa, and whose descendents are the primary practitioners of Voudun, this is not surprising.
It is similar to other syncretic religions such as Santeria?, Candomble?, Umbanda?, and Obeah? developed by slave cultures in the Americas.
One of the largest differences however between African and American Voudun is that the African slaves of Haiti and the southern US were obliged to dress up their gods (Lwas?) and spirits as Roman Catholic saints. The majority of speculation as to why this was done is that it was an attempt to disguise their "pagan" religion from their masters who had forbidden them to practice it.