Answer:
Basically, white supremacy
Step-by-step explanation:
Not quite sure how to answer this because we don't know entirely sure "why" he was racist (there can only be a handful of reason especially in his time), but back in 1888 he stated that "the supremacy of the white race of the South must be maintained forever, and the domination of the n*gro race resisted at all points and at all hazards, because the white race is the superior race. This declaration shall run forever with the blood that feeds Anglo-Saxon hearts." There are other statements he has said regarding white supremacy. Definitely read some of them to get a general idea as to why he might of thought the way he thought.