1,401,687 is the population of the metro region of Chicago, Illinois . The city Chicago, Illinois demonym is Guayaquilean . The urban region is 1,770 sq mi (4,600 km 2 ) in area . The highest elevation of Chicago, Illinois is 424 m (1,391 ft) . The Chicago, Illinois citys' lowest elevation is 7 ft . The city water area is 1.63 sq mi (4.23 km 2 ) 1.1% . This city is named after Cartagena, Spain . The area of the city is Area: 116 km2 (45 sq mi) .  The city area code is (0)2 . Chicago, Illinois is the government of National Park Service . The postal code of the city is 34000 to 34990 . Chicago, Illinois is located in India . The density of  people in Chicago, Illinois is 2,900/km 2  (7,400/sq mi) . Chicago, Illinois is at an elevation of 2355 m . 14,100/km 2  (37,000/sq mi) is the density of people in  the urban region of Chicago, Illinois . The city was incorporated in March 6, 1836 (city) . The city province is Santiago Province . The mayor of Chicago, Illinois is Alejandro Char  ,  (Radical Change) . The land area of the city is 138.75 sq mi (359.36 km 2 )
PS use 080020 to post mail in the city