American Experience asked sociologist and Ku Klux Klan scholar David Cunningham to provide responses to the five questions he is most frequently asked about the Klan. The author of Klansville, U.S.A.: The Rise and Fall of the Civil Rights-Era KKK (Oxford University Press, 2013), Cunningham is Professor and Chair of Sociology at Brandeis University.

Before discussing the most pressing questions people tend to have about the KKK, let me add some background for basic context. The Ku Klux Klan was first formed in 1866, through the efforts of a small band of Confederate veterans in Tennessee. Quickly expanding from a localized membership, the KKK has become perhaps the most resonant representation of white supremacy and racial terror in the U.S. Part of the KKK's enduring draw is that it refers not to a single organization, but rather to a collection of groups bound by use of now-iconic racist symbols -- white hoods, flowing sheets, fiery crosses -- and a predilection for vigilante violence. The Klan's following has tended to rise and fall in cycles often referred to as "waves." The original KKK incarnation was largely halted following federal legislation targeting Klan-perpetrated violence in the early 1870s. The Klan's second -- and largest -- wave peaked in the 1920s, with KKK membership numbering in the millions. Following the second-wave Klan's dissolution in the early 1940s, self-identified KKK groups also built sizable followings during the 1960s, in reaction to the rising Civil Rights Movement. Various incarnations have continued to mobilize since -- often through blended affiliations with neo-Nazi, neo-Confederate, and Christian Identity organizations -- but in small numbers and without significant impact on mainstream politics.

The AMERICAN EXPERIENCE documentary Klansville, U.S.A. focuses on the civil rights-era KKK and tells the story of Bob Jones, the most successful Klan organizer since World War II. Beginning in 1963, Jones took over the North Carolina leadership of the South's preeminent KKK organization, the United Klans of America, and by 1965 his "Carolina Klan" boasted more than 10,000 members across the state, more than the rest of the South combined. Jones' story illuminates our understanding of the KKK's long history generally, and in particular provides a lens to consider the questions that follow.

1. How big a threat is the KKK in the U.S. today?
In an important sense, this may be the key question about the KKK and whether we should still worry, or care, about the Klan today. Likely for that reason, literally every discussion I've had about the Klan -- whether in classrooms, community events, radio interviews, or cocktail parties -- comes around to some version of this concern. I typically respond, in short, that a greater number of KKK organizations exist today than at any other point in the group's long history, but that nearly all of these groups are small, marginal, and lacking in meaningful political or social influence.

I might add two caveats to that reassuring portrait, however. The first is that marginal, isolated extremist cells themselves can become breeding grounds for unpredictable violence. At the peak of his 1960s influence, Bob Jones would often tell reporters that, if they were truly concerned about violence perpetrated by Klan members, their greatest fear should be that he would disband the KKK, leaving individual members to commit mayhem free from the structure imposed by the group. As Jones' followers committed hundreds of terrorist acts authorized by KKK leadership, his claim was of course disingenuous, but it also contained a grain of truth: Jones and his fellow leaders did dissuade members -- many of whom combined rabid racism with unstable aggression -- from engaging in violence not approved by the KKK hierarchy. In the absence of a broader organization with much to lose from a crack-down by authorities, racist violence can be much more difficult to prevent or police.

The second caveat stems from KKK's history of emerging and receding in pronounced "waves." Between the group's periods of peak influence -- say, during the 1880s, or in the 1940s, or the 1980s -- the Klan's fortunes have always appeared moribund. But in each case, some "reborn" version of the KKK has managed to rebound and survive. So, while today the KKK appears an anachronism and, perhaps, less of a threat than other brands of racist hate, we still should vigilantly oppose racist entrepreneurs who seek to exploit the historical cachet of the KKK to organize new campaigns advancing white supremacist ends. To me, this is one primary lesson from the KKK's past, and a compelling reason not to forget or dismiss the enduring relevance of that history.

2. Has the KKK had any lasting political impact?
By most straightforward measures, the KKK appears a failed social movement. Despite the Klan's political inroads during the 1920s, when millions of its members succeeded in electing hundreds of KKK-backed candidates to local, state, and even federal office, the group proved unable to preserve its influence at the ballot box beyond that decade. Later KKK waves have never been able to deliver on promises to rebuild this influential Klan voting bloc. Bob Jones' Carolina Klan came the closest to winning such influence, with mainstream candidates currying favor (sometimes publicly, and more often covertly at Klan rallies and other events) with Jones and other leaders in 1964 and 1968. But that effort appeared short-lived, with both Jones and the Carolina Klan all but disappearing by the early 1970s.

More generally, the KKK's commitment to white supremacy, most clearly realized through Jim Crow-style segregation that endured for decades in the South, has by any formal measure receded as a real possibility in the U.S. However, in less overt ways, the KKK's impact can still be felt. Recent studies that I've undertaken with fellow sociologists Rory McVeigh and Justin Farrell have demonstrated how counties in which the KKK was active during the 1960s differ from those in which the Klan never gained a foothold in two important ways.

First, counties in which the Klan was present during the civil rights era continue to exhibit higher rates of violent crime. This difference endures even 40 years after the movement itself disappeared, and certainly isn't explained by the fact that former Klansmen themselves commit more crimes. Instead, the Klan's impact operates more broadly, through the corrosive effect that organized vigilantism has on the overall community. By flouting law and order, a culture of vigilantism calls into question the legitimacy of established authorities and weakens bonds that normally serve to maintain respect and order among community members. Once fractured, such bonds are difficult to repair, which explains why even today we see elevated rates of violent crime in former KKK strongholds.

Second, past Klan presence also helps to explain the most significant shift in regional voting patterns since 1950: the South's pronounced move toward the Republican Party. While support for Republican candidates has grown region-wide since the 1960s, we find that such shifts have been significantly more pronounced in areas in which the KKK was active. The Klan helped to produce this effect by encouraging voters to move away from Democratic candidates who were increasingly supporting civil rights reforms, and also by pushing racial conflicts to the fore and more clearly aligning those issues with party platforms. As a result, by the 1990s, racially-conservative attitudes among southerners strongly correlates with Republican support, but only in areas where the KKK had been active.

3. Is the KKK a movement mostly in the rural South?
While many of the Klan's most infamous acts of deadly violence -- including the 1964 Freedom Summer killings, the 1965 murder of civil rights activist Viola Liuzzo, and the 1981 lynching of Michael Donald that led to the 1987 lawsuit that ultimately put the United Klans of America out of business for good -- occurred in the Deep South, during the 1920s the KKK was truly a national movement, with urban centers like Detroit, Portland, Denver, and Indianapolis boasting tens of thousands of members and significant political influence.

Even in the 1960s, when the KKK's public persona seemed synonymous with Mississippi and Alabama, more dues-paying Klan members resided in North Carolina than the rest of the South combined. KKK leaders found the Tar Heel State fertile recruiting ground, despite -- or perhaps because of -- the state's progressive image, which enabled the Klan to claim that they were the only group that would defend white North Carolinians against rising civil rights pressures. While this message resonated in rural areas across the state's eastern coastal plain, the KKK built a significant following in cities like Greensboro and Raleigh as well.

Today, the Southern Poverty Law Center reports active KKK groups in 41 states, though nearly all of those groups remain marginal with tiny memberships. So, while the KKK originated after the Civil War as a distinctly southern effort to preserve the antebellum racial order, its presence has extended well beyond that region throughout the 20th and 21st centuries.

4. Why do KKK members wear white hoods and burn crosses?
Some of the most recognizable Klan symbols date back to the group's origins following the Civil War. The KKK's white hoods and robes evolved from early efforts to pose as ghosts or "spectral" figures, drawing on then-resonant symbols in folklore to play "pranks" against African-Americans and others. Such tricks quickly took on more politically sinister overtones, as sheeted Klansmen would commonly terrorize their targets, using hoods and masks to disguise their identities when carrying out acts of violence under the cover of darkness.

Fiery crosses, perhaps the Klan's most resonant symbol, have a more surprising history. No documented cross burnings occurred during the first Klan wave in the 19th century. However, D.W. Griffith's epic 1915 film The Birth of a Nation, which adapted Thomas F. Dixon, Jr.'s novels The Clansman and The Leopard's Spots to portray the KKK as heroic defenders of the Old South and white womanhood generally, drew on material from The Clansman to depict a cross-burning scene. The symbol was quickly appropriated by opportunistic KKK leaders to help spur the group's subsequent "rebirth."

Through the 1960s, Klan leaders regularly depicted the cross as embodying the KKK's Christian roots -- a means to spread the light of Jesus into the countryside. A bestselling 45rpm record put out by United Klans of America included the Carolina Klan's Bob Jones reciting how the fiery cross served as a "symbol of sacrifice and service, and a sign of the Christian Religion sanctified and made holy nearly 19 centuries ago, by the suffering and blood of 50 million martyrs who died in the most holy faith." He emphasized cross burnings as "driv[ing] away darkness and gloom… by the fire of the Cross we mean to purify and cleanse our virtues by the fire on His Sword." Such grandiose rhetoric, of course, could not dispel the reality that the KKK frequently deployed burning crosses as a means of terror and intimidation, and also as a spectacle to draw supporters and curious onlookers to their nightly rallies, which always climaxed with the ritualized burning of a cross that often extended 60 or 70 feet into the sky.

5. Has the KKK always functioned as a violent terrorist group?
The KKK's emphasis on violence and intimidation as a means to defend its white supremacist ends has been the primary constant across its various "waves." Given the group's brutal history, validating Klan apologists who minimize the group's terroristic legacy makes little sense. However, during the periods of peak KKK successes in both the 1920s and 1960s, when Klan organizations were often significant presences in many communities, their appeal was predicated on connecting the KKK to varied aspects of members' and supporters' lives.

Such efforts meant that, in the 1920s, alongside the KKK's political campaigns, members also marched in parades with Klan floats, pursued civic campaigns to support temperance, public education, and child welfare, and hosted a range of social events alongside women's and youth Klan auxiliary groups. Similarly, during the civil rights era, many were drawn to the KKK's militance, but also to leaders' promises to offer members "racially pure" weekend fish frys, turkey shoots, dances, and life insurance plans. In this sense, the Klan served as an "authentically white" social and civic outlet, seeking to insulate members from a changing broader world.

The Klan's undoing in both of these eras related in part to Klan leaders' inability to maintain the delicate balancing act between such civic and social initiatives and the group's association with violence and racial terror. Indeed, in the absence of the latter, the Klan's emphasis on secrecy and ritual would have lost much of its nefarious mystique, but KKK-style lawlessness frequently went hand-in-hand with corruption among its own leaders. More importantly, Klan violence also often resulted in a backlash against the group, both from authorities and among the broader public.