Actually, voodoo is African in origin. It would rise around the 17th century, and has its foundation in West African religions. Shamanism is more Native American. As for whether or not necromancy is among Voodoo practices... well, most practitioners are highly respectful of the spirits, be they departed lives, or as patrons of the world’s aspects. But, just like many things, it is the user who determines what that power is used for.

Voodoo is ritualistic, and involves communication with spirits. It should not be considered evil or dark.