In which John Green teaches you about railroads, and some of the ways they changed the world, and how they were a sort of microcosm for the Industrial Revolution as a whole. Prior to the invention of steam powered railroads, pretty much all locomotion had been muscle-powered. You either walked where you wanted to go, or rode on an animal to get where you were going. The railroad changed human perc
License: CC BY-NC-SA by Khan Academy