I want to know the answer to the following question:
What are some historical reasons multiracial Americans have been classified as black?
All the background I'm provided with is that "Many of majority European ancestry and appearance "married white" and assimilated into white society for its social and economic advantages, such as generations of families identified as Melungeons, now generally classified as white but demonstrated genetically to be of European and sub-Saharan African ancestry.". Is that enough to answer the question?