Long before the artist Philip Guston was celebrated for his cartoonish paintings of pink flesh, cigarettes, and Klansmen, he was Phillip Goldstein, a member of the Los Angeles socialist Bloc of Mural Painters, and a kid on a road trip. In 1934, he and fellow painter Reuben Kadish bought a Ford coupe for $23 and drove to the city of Morelia, Mexico, where the university there had offered the artists a wall to embellish. Guston and Kadish’s fresco, depicting a swastika, hammer and sickle, cross, whips, nails, and electric chair cap, would go by many titles: The Struggle against War and Fascism; The Workers’ Struggle for Liberty, as Time magazine dubbed it; and The Struggle against Terrorism.

The Morelia mural swarms with robed men in peaked white hoods, suggesting one particular kind of terrorism for viewers then and now. But in 1934, when the mural was painted, the Ku Klux Klan’s white hood had been standardized for only two decades. How the Ku Klux Klan’s white hood came to be an icon of hatred is the story of image-makers: parade planners and playwrights, Hollywood and the mail-order catalog. Before they came along, though, the early Klan of the postwar South really was an “Invisible Empire,” emphasis on the invisibility: covert, decentralized, lacking hierarchy or uniforms, including the now-standard white, conical hood.

As historian Elaine Frantz Parsons has written in Midnight Rangers: Costume and Performance in the Reconstruction-Era Ku Klux Klan, while some early Klansmen did wear white, and later Klan mythology would claim they’d dressed up as Confederate ghosts, they usually drew on folk traditions of carnival, circus, minstrelsy, Mardi Gras—or the mid-century “Calico Indians,” hooded and masked farmers rebelling against upstate New York land laws. Klansmen wore gigantic animal horns, fake beards, coon-skin caps, or polka-dotted paper hats; they imitated French accents or barnyard animals; they played guitars to serenade victims. Some Klansmen wore pointed hats suggestive of wizards, dunces, or Pierrots; some wore everyday winter hoods, pillowcases, or flour sacks on their heads. Many early Klansman also wore blackface, simultaneously scapegoating and mocking their victims.

24th May 1965: Members of the Ku Klux Klan in white uniforms and hoods at a meeting in Beaufort, South Carolina. Harry Benson / Getty Images

The lack of a formal uniform helped apologists like John H. Christy, a former Georgia Representative, testify to Congress in 1871: “Sometimes mischievous boys who want to have some fun go on a masquerading frolic to scare the negroes, but they do not interrupt them, do not hurt them in any way…stories are exaggerated, and it keeps up the impression among the negroes that there is really a Ku-Klux organization.” But pantomime costumes didn’t make the early Klan any less real, or brutal: one “colored” witness, Jacob Montgomery of Spartanburg, South Carolina, testified that the Klansmen who pistol-whipped, beat, and kicked him wore “white gowns, and some had flax linen, and some had red calico, and some red caps, and white horns stuffed with cotton. And some had flannel around coon-skin caps.” Another witness, Henry Lipscomb, testified that the Klan had killed two of his black neighbors and one white; they’d stripped, choked, and beaten him, and thrown a fireball into his house. The original Klan, anonymous, unaccountable, and hybrid, springing up in a woman’s gown, squirrel skin, or Venetian domino mask, violated its victims, then vanished, denying that any terrorism had occurred.

As Reconstruction ended and Southern white men reclaimed political power, they dropped out of the Klan, no longer limited to secret outlets for their violence. In 1872, the old Klan made a valedictory appearance: in public, in the Memphis Mardi Gras parade, revealing a new kind of pageantry that was no less ceremonial than chilling. Local Klan leaders and representatives from all the Southern states rode their own float, wearing black, conical hats with the skull and crossbones and “K.K.K.” in white. They staged the mock lynching of a man in blackface; they lassoed black spectators. The Klan itself was dying, but only because white supremacy was resurging right out in the open, with the sanction and participation of law enforcement and white society at large. Now they had Jim Crow laws. They had a criminal justice system that disproportionately punished Black people and imprisoned them in prison farms, on former plantations. They had lynch mobs, who no longer concealed their identities.