Like Fight Club, there were rules about joining the secret society known as the Order of the Star Spangled Banner (OSSB). An initiation rite called “Seeing Sam.” The memorization of passwords and hand signs. A solemn pledge never to betray the order. A pureblooded pedigree of Protestant Anglo-Saxon stock and the rejection of all Catholics. And above all, members of the secret society weren’t allowed to talk about the secret society. If asked anything by outsiders, they would respond with, “I know nothing.”

So went the rules of this secret fraternity that rose to prominence in 1853 and transformed into the powerful political party known as the Know Nothings. At its height in the 1850s, the Know Nothing party, originally called the American Party, included more than 100 elected congressmen, eight governors, a controlling share of half-a-dozen state legislatures from Massachusetts to California, and thousands of local politicians. Party members supported deportation of foreign beggars and criminals; a 21-year naturalization period for immigrants; mandatory Bible reading in schools; and the elimination of all Catholics from public office. They wanted to restore their vision of what America should look like with temperance, Protestantism, self-reliance, with American nationality and work ethic enshrined as the nation's highest values.

Know Nothings were the American political system’s first major third party. Early in the 19th century, two parties leftover from the birth of the United States were the Federalists (who advocated for a strong central government) and the Democratic-Republicans (formed by Thomas Jefferson). Following the earliest parties came the National Republicans, created to oppose Andrew Jackson. That group eventually transformed into the Whigs as Jackson’s party became known as the Democrats. The Whig party sent presidents William Henry Harrison, Zachary Taylor and others to the White House during its brief existence. But the party splintered and then disintegrated over the politics of slavery. The Know Nothings filled the power void before the Whigs had even ceased to exist, choosing to ignore slavery and focus all their energy on the immigrant question. They were the first party to leverage economic concerns over immigration as a major part of their platform. Though short-lived, the values and positions of the Know Nothings ultimately contributed to the two-party system we have today.

Paving the way for the Know Nothing movement were two men from New York City. Thomas R. Whitney, the son of a silversmith who opened his own shop, wrote the magnum opus of the Know Nothings, A Defense of the American Policy. William “Bill the Butcher” Poole was a gang leader, prizefighter and butcher in the Bowery (and would later be used as inspiration for the main character in Martin Scorsese’s Gangs of New York). Whitney and Poole were from different social classes, but both had an enormous impact on their chosen party—and their paths crossed at a pivotal moment in the rise of nativism.

In addition to being a successful engraver, Whitney was an avid reader of philosophy, history and classics. He moved from reading to writing poetry and, eventually, political tracts. “What is equality but stagnation?” Whitney wrote in one of them. Preceded in nativist circles by such elites as author James Fenimore Cooper, Alexander Hamilton, Jr. and James Monroe (nephew of the former president), Whitney had a knack for rising quickly to the top of whichever group he belonged to. He became a charter member of the Order of United Americans (the precursor to the OSSB) and used his own printing press to publish many of the group’s pamphlets.

Whitney believed in government action, but not in service of reducing social inequality. Rather, he believed, all people “are entitled to such privileges, social and political, as they are capable of employing and enjoying rationally.” In other words, only those with the proper qualifications deserved full rights. Women’s suffrage was abhorrent and unnatural, Catholics were a threat to the stability of the nation, and German and Irish immigrants undermined the old order established by the Founding Fathers.

From 1820 to 1845, anywhere from 10,000 to 1000,000 immigrants entered the U.S. each year. Then, as a consequence of economic instability in Germany and a potato famine in Ireland, those figures turned from a trickle into a tsunami. Between 1845 and 1854, 2.9 million immigrants poured into the country, and many of them were of Catholic faith. Suddenly, more than half the residents of New York City were born abroad, and Irish immigrants comprised 70 percent of charity recipients.

As cultures clashed, fear exploded and conspiracies abounded. Posters around Boston proclaimed, “All Catholics and all persons who favor the Catholic Church are…vile imposters, liars, villains, and cowardly cutthroats.” Convents were said to hold young women against their will. An “exposé” published by Maria Monk, who claimed to have gone undercover in one such convent, accused priests of raping nuns and then strangling the babies that resulted. It didn’t matter that Monk was discovered as a fraud; her book sold hundreds of thousands of copies. The conspiracies were so virulent that churches were burned, and Know Nothing gangs spread from New York and Boston to Philadelphia, Baltimore, Louisville, Cincinnati, New Orleans, St. Louis and San Francisco.

At the same time as this influx of immigrants reshaped the makeup of the American populace, the old political parties seemed poised to fall apart.

“The Know Nothings came out of what seemed to be a vacuum,” says Christopher Phillips, professor of history at University of Cincinnati. “It’s the failing Whig party and the faltering Democratic party and their inability to articulate, to the satisfaction of the great percentage of their electorate, answers to the problems that were associated with everyday life.”

Phillips says the Know Nothings displayed three patterns common to all other nativist movements. First is the embrace of nationalism—as seen in the writings of the OSSB. Second is religious discrimination: in this case, Protestants against Catholics rather than the more modern day squaring-off of Judeo-Christians against Muslims. Lastly, a working-class identity exerts itself in conjunction with the rhetoric of upper-class political leaders. As historian Elliott J. Gorn writes, “Appeals to ethnic hatreds allowed men whose livelihoods depended on winning elections to sidestep the more complex and politically dangerous divisions of class.”

No person exemplified this veneration of the working class more than Poole. Despite gambling extravagantly and regularly brawling in bars, Poole was a revered party insider, leading a gang that terrorized voters at polling places in such a violent fashion that one victim was later reported to have a bite on his arm and a severe eye injury. Poole was also the Know Nothings’ first martyr.

On February 24, 1855, Poole was drinking at a New York City saloon when he came face to face with John Morrissey, an Irish boxer. The two exchanged insults and both pulled out guns. But before the fight could turn violent, police arrived to break it up. Later that night, though, Poole returned to the hall and grappled with Morrissey's men, including Lewis Baker, a Welsh-born immigrant, who shot Poole in the chest at close range. Although Poole survived for nearly two weeks, he died on March 8. The last words he uttered pierced the hearts of the country’s Know Nothings: “Goodbye boys, I die a true American.”

Approximately 250,000 people flooded lower Manhattan to pay their respects to the great American. Dramas performed across the country changed their narratives to end with actors wrapping themselves in an American flag and quoting Poole’s last words. An anonymous pamphlet titled The Life of William Poole claimed that the shooting wasn’t a simple barroom scuffle, but an assassination organized by the Irish. The facts didn’t matter; that Poole had been carrying a gun the night of the shooting, or that his assailant took shots to the head and abdomen, was irrelevant. Nor did admirers care that Poole had a prior case against him for assault with intent to kill. He was an American hero, “battling for freedom’s cause,” who sacrificed his life to protect people from dangerous Catholic immigrants.

On the day of Poole’s funeral, a procession of 6,000 mourners trailed through the streets of New York. Included in their number were local politicians, volunteer firemen, a 52-piece band, members of the OSSB—and Thomas R. Whitney, about to take his place in the House of Representatives as a member of the Know Nothing Caucus.

Judging by the size of Poole’s funeral and the Know Nothing party’s ability to penetrate all levels of government, it seemed the third party was poised to topple the Whigs and take its place in the two-party system. But instead of continuing to grow, the Know Nothings collapsed under the pressure of having to take a firm position on the issue the slavery. By the late 1850s, the case of Dred Scott (who sued for his freedom and was denied it) and the raids led by abolitionist John Brown proved that slavery was a more explosive and urgent issue than immigration.

America fought the Civil War over slavery, and the devastation of that conflict pushed nativist concerns to the back of the American psyche. But nativism never left, and the legacy of the Know Nothings has been apparent in policies aimed at each new wave of immigrants. In 1912, the House Committee on Immigration debated over whether Italians could be considered “full-blooded Caucasians” and immigrants coming from southern and eastern Europe were considered "biologically and culturally less intelligent."

From the end of the 19th century to the first third of the 20th, Asian immigrants were excluded from naturalization based on their non-white status. “People from a variety of groups and affiliations, ranging from the Ku Klux Klan to the Progressive movement, old-line New England aristocrats and the eugenics movement, were among the strange bedfellows in the campaign to stop immigration that was deemed undesirable by old-stock white Americans,” writes sociologist Charles Hirschman of the early 20th century. “The passage of immigration restrictions in the early 1920s ended virtually all immigration except from northwestern Europe.”

Those debates and regulations continue today, over refugees from the Middle East and immigrants from Latin America.

Phillips’s conclusion is that those bewildered by current political affairs simply haven’t looked far enough back into history. “One can’t possibly make sense of [current events] unless you know something about nativism,” he says. “That requires you to go back in time to the Know Nothings. You have to realize the context is different, but the themes are consistent. The actors are still the same, but with different names.”