It was founded by Kongzi. He was a Chinese philosopher who lived in the 6th century BCE.
Plessy v. Ferguson set forth the doctrine of "separate but equal" which enabled institutionalized segregation as long as things were "equal"
However, the Court did not define what equal really meant.
So, you might see a bathroom for African-Americans that was a hole in the ground while the whites only bathroom was pristine and modern.
