By the 1870s , Chicago had become the main financial center for the West , but in October 1871 the Great Chicago Fire destroyed the majority of the wooden structures within the city . The city was rebuilt on large plots of land in a new grid network and followed new city ordinances that prohibited construction in wood . These factors encouraged the building of taller properties in new innovative designs , which , like New York , saw a range of businesses and services being packed into single buildings
Great Chicago Fire
Great Chicago Fire
Early skyscrapers