Before the dead-eyed almost-humans in videogames and CG films like The Polar Express, even before the term uncanny valley was coined in 1970, Disney was giving us the willies with lifelike machines. Uncle Walt had a team working on “Audio-Animatronics”—automated puppets that move and speak in sync with recorded audio—back in the late ’40s. But it wasn’t until the 1964 World’s Fair in Flushing Meadows, New York, that the public witnessed the power of Disney’s technology: an army of herky-jerky “humans.”

Four exhibitors—Ford, General Electric, Pepsi-Cola, and the state of Illinois—had enlisted Disney to create “people” for their rides and installations. (Pepsi’s entry? A bevy of sickeningly cute munchkin-bots in a tribute to Unicef called It’s a Small World.) But the state of Illinois stole the show with a simulacrum of Abraham Lincoln that rose from a chair to deliver an oratory cobbled from several of the president’s speeches. Many visitors were convinced it was an actual person. “Lincoln sits, stands, moves his tongue, moves his lips, clears his throat, frowns, smiles, looks skeptical,” newscaster David Brinkley marveled. Still, reporters couldn’t help but note how unsettling the mecha was. Science Digest’s Daniel Cohen wrote of shaking its hand: “Its texture is enough like real flesh to make you cringe. It’s moist, for the vinyl plastic skin exudes a fine oil over a period of time. The plastic even bruises.”

Most of Walt’s Audio-Animatronics from the fair ended up in Disney parks in one form or another. Meanwhile, by 1969 his Imagineers had hit upon the perfect use for the tech: the Haunted Mansion ride, in which the mechanical humanoids are supposed to be scary.