Chicago is the third most populous city in the United States, located in northeastern Illinois on the southwestern shores of Lake Michigan. The city was incorporated in 1837 and experienced major growth and development in the 19th century, though it was set back by the Great Chicago Fire of 1871. Today, Chicago faces various environmental issues related to water, air, energy use, transportation, and climate change that the city is working to address through sustainability initiatives like retrofitting infrastructure, green buildings, and a smart grid.