Why did white southerners (and groups like the KKK) use terror as a weapon in their journey to regain political control of the South?

300 words answer one of this questiond from the attach document  Include references and citations where necessary

Please answer one of the following questions:

  1. Many people believe the failure of Reconstruction was primarily a failure of leadership; how might of the outcome of Reconstruction been different had Lincoln lived?
  2. Why did white southerners (and groups like the KKK) use terror as a weapon in their journey to regain political control of the South?
  3. In 1865 the South began to enact Black Codes targeting freed slaves; how can this action be considered a turning point in Reconstruction?