who or what was responsible for the betrayal of the civil rights agenda of the reconstruction era and the creation of jim crow south?

who or what was responsible for the betrayal of the civil rights agenda of the reconstruction era and the creation of jim crow south?

Explain with detail

and

Which interpretation of industrialists do you find credible and why?

John D Rockefeller, Andrew Carnegie, and Cornelius Vanderbilt are "Captains of the Industry" through their industrial empires

or

John D Rockefeller, Andrew Carnegie, and Cornelius Vanderbilt are "Robber Barons" who made their fortunes through unethical business practices?