For the past 150 years, the Ku Klux Klan has murdered and tortured its way through US history. By reputation it is one of the most notorious and ultra-violent terrorist groups in the world; even today the Klan occasionally rears its ugly, trademarked, hooded head. But the truth is that it has been in terminal decline since the 1960s – and the myth is now far more dangerous than the reality.

From its Civil War origins as an insurgency in the defeated South, the Klan became a mass movement in the 1920s and a byword for bigotry and racism in the civil rights era. Since then, however, its numbers have fallen; yet it remains a potent symbol of white supremacist terror in our polarised world. Drawing on twenty years of primary research, The Ku Klux Klan: An American History seeks to demystify one of the most hated, feared and poorly understood organisations in history.