I will say this, anyone who would like to ascribe the KKK to the old South must understand that like modern Neo-Nazis they're just useful idiots for politicians and men with a silver dollar to their name. What I'm getting at is, rich man bad because they fuck with people too much.
The KKK is mythologized in a very unhelpful way. Firstly, it is basically defunct in the modern day, even within White supremacist circles it's just a joke since it consists of methhead crackers and Feds. Talking about it is like whining about the Weather Underground bombing things, it's several decades too late, but because there are SOME people who OCCASIONALLY march - and do nothing else - it is still kept in people's imaginations as a real thing.
But aside from that, the KKK came in different waves and the image most people have of it is a composite of all three, and the most important Klan, the second, is the one that's least talked about.
First Klan: Basically just a Southern nationalist terrorist organization, wanted to suppress Blacks and Republicans; a terrorist wing of the Democratic Party. It waged a terror campaign for the purpose of overturning Reconstruction, which got it violently suppressed, but was ultimately a success. Sort of like a Pyrrhic victory in reverse (they lost but still got what they wanted in the end).
Second Klan: Essentially an American fascist movement, being based around American nationalism with Jewry, Catholics, non-Whites, ethnic Whites, Communists, labor organizations, and other such. Basically, around the same time Fascism was becoming appealing to the world in general, the socially progressive Civil War generations were starting to fade away. Generations that didn't give a shit about grandpa fighting to free the slaves, but having to deal with mass migrations of Blacks and foreigners into their Northern cities, and distant enough from the war to romanticize it, started seeing Southerners as the same victims that Southerners saw themselves. Nobody was interested in continuing regional animus so they reapproached each other. This tied in heavily with the Progressives (who had both a socialistic and a fascistic side, the two were very muddled back then) like Woodrow Wilson. America never had a prominent fascist political party or a coherent fascist ideology, but the Klan's intense White nativist Protestant identity - an echo of the Know-Nothings, really - was as close as it came. Faded away when progressivism came back but in its more recognizable form under FDR.
THE SECOND KLAN WAS A NATIONAL PHENOMENON. IT WAS NOT SOUTHERN NATIONALIST THOUGH IT USED SOUTHERN IMAGERY. IT EXISTED EVERYWHERE FROM NEW ENGLAND TO THE WEST COAST, THE ROCKIES TO THE SOUTH.
I do regard Woodrow Wilson as being the closest thing America ever had to a Hitler. (I absolutely despise him.)
The Second Klan introduced all the pageantry we recognize as Klan crap now.
Third Klan: Basically just an anti-segregation terrorist organization formed by Southerners, inspired more by the First Klan, but it also had its remnants from the Second Klan as well as people pissed off in places like Wisconsin (Milwaukee) where working class ethnic Whites (like Poles) hated dealing with Blacks. Died a horrible death when the Feds went in and crushed it. Discredited itself by doing disgusting shit like bombing little kids in church.
Some basic Klan myths:
The Klan was just Southern.
One of the biggest states for Klan recruitment was Illinois. California had tons of Klan activity. It was a national phenomenon.
The Klan was just rural.
Major cities had large Klans and Klans tended to form in the cities first.
The Klan was uneducated poors.
The Klan was a tool of the business class against labor organization, like the coal miners in Appalachia. The leadership of the Klan tended to be the same as the civic leaders in public, businessmen, police chiefs, mayors. Respectable people ran the Klan.
That's kind of how they were able to get away with stuff.
Bonus fun fact: The robes come out of Mardi Gras type celebrations, you see Spanish Catholic priests wear similar stuff. The cross burning comes from Scottish culture, carrying a burning cross from village to village was how a lord signaled to his people to prepare for war. It was like a symbolic declaration of war against the Blacks. This was some pageantry made up by
The Clanmsan (Birth of a Nation), sort of astroturfed into being a real thing.
This is only barely related, but you know what people don't tend to talk about with Appalachia?
The time a huge fucking army 10,000 strong, Italian guido immigrants, Blacks, Appalachians, Hungarians, launched an insurrection, spurred on by Communists, against coal mining companies that were trying, unsuccessfully, to use race to turn them on each other. They were fucking bombed by biplanes. The coal miners lived in "company towns" where you were paid in Monopoly money only redeemable at stores (that could then act like a monopsonistic employer and monopolistic grocer, basically trapping you), forced to stay by debt with mine guards that would loom over them with machine guns, searches of houses for unapproved literature, evictions, spies in the mines, murders of union organizers. The National Guard was called out and their stupid, misguided patriotism lead the miners to stop. West Virginia was a dictatorship of the coal companies and across Appalachia people noted that miners did not give a shit about race. But who cares about jerking off the one time America had a little socialist proto-revolution, BIGGEST INTERNAL WAR SINCE THE CIVIL WAR, where White and Black Southerners fought alongside each other.
Battle of Blair Mountain