State of Illinois which is part of the United States, was founded in Dec. 3, 1818. Illinois occupies the 25 place in terms of total area of the US. The area of the state is 149 997 square kilometers. The capital of Illinois is Springfield. The population of Illinois amounts to 12 801 539 people and ranks 5 in terms of population of the US. The largest city of the state is Chicago. Our catalog contains 360 cities and 324 755 enterprises located in this state. Postal abbreviation or short name is IL.