Elevated Trains of Chicago

Chicago, Illinois is famous for its elevated trains, but do you know why they exist?! Find out in this 11 x 17 inch print. Comes with this description:

As the stock yards and butchering industry grew in Chicago, the city was confronted with an unexpected problem: Zombies. Lured from as far as fifty miles by the stench of rotting flesh and city streets running with blood, the Living Dead proved to be quite a problem in the city until the advent of the elevated train. This fast, reliable, and most importantly, stair-based system of transportation meant that citizens could escape from roving hordes of monsters by simply ascending the stairs of an “El” and being whisked away to a safer part of town.