Chicago is in Illinois.

Chicago (English: Chicago) is a city located in Illinois, United States. It is the county seat of Cook County. It is also a hub city in the Midwest of the United States. It borders Lake Michigan to the east and has a population of approximately 2.72 million. It is located in the center of the North American continent and is an important railway and aviation hub in the United States. It is also one of the major financial, futures and commodity trading centers in the United States.

Economic development:

Chicago is the metropolitan area with the third highest GDP in the United States (after New York and Los Angeles). In 2010, the GDP reached 532 billion US dollars. In September 2017, it reached $670.5 billion. At the same time, the metropolitan area was also rated as the most balanced economy in the United States. It is ranked as the fourth most important business center in the world by the Mastercard Global Trade Center Index.

In addition, the number of new businesses in the Chicago metropolitan area ranked first in the United States for six of the seven years from 2001 to 2008. The city’s scientific and technological innovation also ranks third in the United States. In 2009, the city was ranked the ninth richest city in the world by UBS.

Reference for the above content: Baidu Encyclopedia-Chicago