

The importation of slaves had been banned in the US since 1808, about 60 years before 14th amendment. The vast majority, if not all, of the people that were granted citizenship by the 14th amendment would have been born in the US and been several generations removed from anyone that lived in Africa.
It’s the exact same mistake that racists keep making: Assuming that any brown person that they see is from some other country.

The sugar also supplies a significant amount of the volume of the product. Artificial sweetener is significantly sweeter than sucrose, like hundreds of times sweeter, so just swapping the sugar for artificial sweetener would require them to use a bulking agent. The safest bulking agent that doesn’t change the flavor or texture would be sugar.