David J. Chalmers 
Hooded Americanism [PDF ebook] 
The History of the Ku Klux Klan

"The only work that treats Ku Kluxism for the entire period of it’s existence . . . the authoritative work on the period. Hooded Americanism is exhaustive in its rich detail and its use of primary materials to paint the picture of a century of terror. It is comprehensive, since it treats the entire period, and enjoys the perspective that the long view provides. It is timely, since it emphasizes the undeniable persistence of terrorism in American life."-John Hope Franklin