The Klu Klux Klan or the 'KKK' can be divided into 4 separate and distinct movements with completely different objectives. The commonly held historical narrative conflates the four very different organizations as a single underground entity perpetually carrying out racial oppression, using violence and terrorism. This is not true.
The original KKK emerged just following the Civil War as an insurgency to counter Reconstruction, which began in 1865. The federal government shut that KKK version down by 1871.
The third incarnation of the KKK emerged in the 1950's and 1960's, largely a collection of disparate ad hoc local groups, infrequently using terrorism to protest desegregation in the South.
The KKK that marched against the civil rights movement of the 1960's was not organized on a national basis. Members were often unaware of the Klan's history and the symbols they were using.
The KKK of the 1950's and 1960's mostly died out by the 1970's. Today, a 4th incarnation of a small number of KKK groups are evident in protests over removal of the Confederate flag and Southern heritage monuments. A KKK branch in Montana is publicly recruiting African-Americans and Latinos.
In less than 3 minutes of film, Martin Scorsese sums up the historic American conflict between natives and Catholic immigrants in "Gangs of New York."
THE BURNING CROSS
The KKK'S burning cross was an antichristian sacrilege, most often used in the second incarnation of the KKK. That KKK began about 1915 as a formal and legal organization. They were not involved in racial politics at all but rather advocated nativism. This organization was a transparent and public fraternity. They were known to oppose Catholicism, but mostly through legal means.
That KKK were the first real advocates for the separation of church and state, meant to counter their fear that Catholicism would take control of American politics. They feared the Vatican would manipulate the American system through the growing Catholic population of the USA.
Hugo Black, appointed by FDR to SCOTUS, wrote the opinion in the 1947 case Everson v. Board of Education, put forth the novel interpretation that the First Amendment’s establishment clause applied to the states and that any government support or preference for religion amounts to an unconstitutional establishment of religion.
Justice Black, in one of the first examples of perverse judicial activism, cobbled together this legal fiction by building on Jefferson's infamous phrase of 'separation of church and state.' The now well-known expression from a little-known Thomas Jefferson letter lay dormant for nearly a century and a half until Supreme Court Justice Hugo Black resurrected it. While the concept was almost unknown among the populace, separation of church and state was very much on the mind of Black's KKK peers.
Garland Goff makes clear Black's motives stemmed from his nativist and antichristian KKK philosophies:
...one should form a belief that Justice Black was definitely biased against religion, especially the Catholic Church, and became a judicial activist bent on removing any inclinations of religion out of government.
Despite his denials of prejudice, Justice Black was a member of the Ku Klux Klan, which promoted the concept of separation of church and state based on Catholic prejudices. As a Klan member, Justice Black gave speeches denouncing the Catholic Church and the supposed infiltration of the Church into the government.
He administered oaths to new Klan members that supported the separation of church and state. Justice Black was even uncomfortable with his own faith. He finally concluded that religion was good for some, but he did not need it.
Therefore, he built a high and impregnable wall against religion that today has been twisted and used to eliminate inclinations that God exists in the name of religious freedom.
POTUS Thomas Jefferson assured the Danbury Baptists that Christian sect diversity would be protected. A wall between the federal government and the (Christian faith promoting) state governments could not be breached. In 1947, former Klu Klux Klansman SCOTUS Hugo Black perversely turned Jefferson's phrase "separation of church and state" to separate the church from all government. The Founders never intended to protect a diversity of non-Christian religions or no religion.
Not surprisingly, the antichristian KKK sent funds to the Mexican government in support of their war to crush the Catholic Church in Mexico. This nativist KKK died out in the 1940's.
Why the KKK hatred toward Catholics, who are supposedly fellow Christians?
Edward Condon makes sense of it by stating the obvious: the KKK was NEVER a Christian organization:
The Klan’s signature calling card, a burning cross, far from being Christian, is an act of Christian sacrilege. It was chosen without any reference to Christianity at all. Instead, it harkens back to an old Scottish Highland signal declaring a blood-feud and summoning the clan for a vendetta campaign.
The first iteration of the Klan did not last long: It was suppressed by the Federal government in 1871. It was another Freemason, William Joseph Simmons, who later revived it in the 1920s, and the KKK began its spread across the country. During this period, it was the Masonic Lodges that proved their most fertile recruiting ground.
The enduring cultural assumption is that since the Ku Klux Klan was formed in the deeply Protestant communities of the southern United States, the two must be linked. In fact, the Klan, like the Masons before them, were denounced by the local pastors. The group attracted a class of men far more interested in white power, anti-Catholicism, anti-Semitism, and esoteric philosophy than in Christianity.
While there is absolutely no evidence that the founding of the KKK was a deliberate Masonic project, it was the shared passions of segregation, anti-Catholicism, and preserving and advancing Anglo-Saxon status in America in the face of rising immigration and racial equality that led so many Masons to join. In Oregon, the Masons and the Klan fielded joint candidates for election to state office, and they even launched a successful joint campaign to outlaw religious schools.
We can see that the driving forces behind the Klan, much like slavery, were godless secularist philosophies, neopaganism and tribalism. Christianity was rejected by slave-owners and the KKK.
Ironically the legacy of the KKK was the radical 'separation of the church and state' precedent, which the left continues to use as a legal hammer to deChristianize America today.