The water area of the city is 129.3 km 2  (49.9 sq mi) . The highest elevation of Chicago, Illinois is 2,715 m (8,907 ft) . The lowest elevation of Chicago, Illinois is 246 ft . 36°18′N 59°36′E﻿ / ﻿36.300°N 59.600°E are the coordinates of the city. . Kakha Kaladze is the mayor of Chicago, Illinois . The postal code of the city is 8320000 . The population of the urban region is 3,435,394 . Chicago, Illinois is named for Christ Church, Oxford . Chicago, Illinois is the government of Parks Canada .  The city area code is (+593) 4 . The city was incorporated in 1 October 1984 . The province of the city Chicago, Illinois is Gauteng . Chicago, Illinois is at an elevation of 1050 ft . The city land area is 8.921 sq mi (23.106 km 2 ) . The density of  inhabitents in  the urban region of Chicago, Illinois is 3,300/km 2  (8,600/sq mi) . Population (2012): 3,937,451 is the population of Chicago, Illinois . The area of the metro region is 4,558.4 sq km (1,760.0 sq mi) . The demonym of the city Chicago, Illinois is Alexandrian, Alexandrine (Arabic: إسكندراني‎) . Chicago, Illinois is located in Zulia
Chicago, Illinois was legally declared as a city in 1 October 1984