Art by Andy Warhol

Warhol wanted to be a machine, in his own words, and the Factory (his silver-foiled Manhattan studio, part production line, part 24-hour social scene) was built to make that literal. Silkscreening let him and a rotating crew of assistants reproduce the same Marilyn Monroe or Campbell's Soup Can image dozens of times with small variations, treating repetition itself as the subject rather than a shortcut to one. He was drawing a straight line between advertising, celebrity, and fine art at a moment when most of the art world still treated that line as sacred.

He also made films almost nobody has actually sat through in full: Sleep is five hours and twenty minutes of a man sleeping; Empire is eight hours of a static shot of the Empire State Building at dusk. They weren't really meant to be watched start to finish so much as experienced as duration, an idea that shows up constantly in performance and video art decades later.

In 1968, Valerie Solanas, a writer who'd had a small, tense association with the Factory and had written a radical feminist manifesto called SCUM, walked in and shot him three times, very nearly killing him. He survived, but the Factory's freewheeling, anyone-welcome atmosphere never fully returned; Warhol grew visibly more guarded for the rest of his life, even as his commercial success kept climbing.