Ramification (noun) – the act or process of branching

Source: https://www.merriam-webster.com/dictionary/ramification

From “The Complete Fiction of Nella Larson” by Nella Larsen, Page 43

“Negro society, she had learned, was as complicated and as rigid in its ramifications as the highest strata of white society.”

The author uses this word to describe how the Negro Society has many layers or branches in it. This shows that the Negro Society is big, and contains various divisions that are complex.