Chicago is a city positioned along Lake Michigan and is the most populous city in both the state of Illinois and the Midwestern United States. Now the third most populous city in the US, Chicago was incorporated as a city in 1837 between the Great Lakes and Mississippi River Watershed and grew rapidly in the mid-nineteenth century. In 1871, the Great Chicago Fire destroyed several square miles, leaving 100,000 people homeless, and consequently prompted accelerated construction and development, including the construction of the city's first skyscraper in 1885.