Elisha Otis invented an automatic safety brake for elevators in 1854. At the New York World's Fair, he cut an elevator rope with an axe to prove it worked. The demonstration convinced people elevators were safe, leading to taller buildings and the age of skyscrapers.
The elevator gets invented, but people didn't want to use them. They're scared because there were situations where elevators would just plummet. So it's like, okay, no thanks. The consequence of that is you don't have elevators, you don't have tall buildings. New York was like 4 stories high. This guy Otis ends up creating an elevator with automatic brakes. He's like, this is it, this is going to be amazing, everybody's gonna buy my elevators. But it didn't happen right away, and nobody believed him. The World Fair was going on, and Otis decides to go all in. So he creates this exhibit where he's got an elevator suspended in the air, hanging by ropes. He stands in an elevator and he says, "Ladies and gentlemen, I have created the world's first safe elevator with automatic brakes." And he gets the guy at the top to swing an axe and he cuts one rope and the elevator starts swaying and swinging. Everyone's gasping in the crowd and he's like, "Cut the rope!" Elevator starts to go down 2 feet and then it automatic brakes and it stops and he says, "All safe, gentlemen." And he says something like, "When you're in an Otis elevator, all's well, you will be safe." And elevator sales take off from there. It literally reshaped the way that cities work.
