The 20th to 21st century Klan actually formed after the Civil War, during the Reconstruction period. Then it was entirely contained within the South, mostly in the rural South. It [was] all men. There were violent attacks on people who were engaged, or [wanted] to be engaged, in the Reconstruction state, [including] freed blacks, southern reconstructionists, politicians and northerners who move to the South. That collapses for a variety of reasons in the 1870s.
Then, the Klan is reborn in the teens, but becomes really big in the early 1920s. And that is the second Klan. That is probably the biggest organized outburst of white supremacy in American history, encompassing millions of members or more. ... And that's not in the South, [it's] primarily in the North. It's not marginal. It runs people for office. It has a middle class base. They have an electoral campaign. They are very active in the communities. And they have women's Klans, who are very active and very effective in some of the communities. That dissolves into mostly scandals around the late '20s.
Then there's some fascist activity around the wars — pro-German, some Nazi activity in the United States — not sizable, but obviously extremely troubling.
The Klan and white supremacy reemerge in a bigger and more organized way around the desegregation and civil rights movement — again, mostly in the South, and back to that Southern model: vicious, violent, defensive, Jim Crow and white rights in the South.
And then it kind of ebbs. After a while, it kind of comes back again in the late '80s and the early 21st Century as another era. And then there's kind of a network of white supremacism that encompasses the Klan, which is more peripheral by this time. Also Neo-Nazi influence is coming as white power skinheads, racist music, and also neo-Nazi groups. The Klans tend to be super nationalist, but these neo-Nazi groups have a big international agenda.
Then the last wave is where we are now, which is the Internet appears. The movement has been in every other era as movement of people in physical space like in meetings, rallies, protests and demonstrations and so forth. It becomes primarily a virtual world, and as you can see, has its own consequences — many consequences. It's much harder to track. And then there are these blurred lines between all these various groups that get jumbled together as the alt-right and people who come from the more traditional neo-Nazi world. We're in a very different world now.