Mumbo jumbo--nonsense?

Having grown up hearing the phrase mumbo jumbo used frequently with the connotation of meaningless, I never thought to look into the etymology of the expression as it seemed so insignificant. The word itself seems to come from jumbled origins, with its clear roots lost to American culture over time.  An 18th century entry in the Oxford English Dictionary lists mumbo jumbo as "...a grotesque idol...said to have been worshipped by some tribes. Mumbo Jumbo is an object of senseless veneration or a meaningless ritual.". This obviously dismissive treatment of African culture may have been representative of the views that led to our eventual colloquial use of the phrase.  According to Reed, or the American Heritage Dictionary of the English Language, mumbo jumbo comes from a Mandingo word that literally translates to "magician who makes the troubled spirits of ancestors go away". Other sources, however, claim that mumbo jumbo stems from the Mandingo word maamajomboo, which refers to "a masked dancer that took part in religious ceremonies". Whatever its true meaning may have been, it seems more or less certain that it arises from the Mandingo language. Further research informed me that Mandingo isn't actually one concrete language, but a sort of family of languages (including Malinke, Maninka, and Bambara) spoken across western Africa. From learning this I realized just how extensive my ignorance of African history and culture truly is. This may have to do with the fact that I don't consciously go out of my way to seek more knowledge, but I think is mostly owed to the fact that American schools have almost entirely kept African history out of their curriculum. Despite the sheer number of African "immigrants" that were made to find new lives in America, their cultures were forcibly stripped and stolen from them, and did not get a chance to live on into the mainstream. Dehumanization was a tool used for years in antebellum America, and in the process a rich culture was lost and tossed aside as mumbo jumbo.