Illinois is dominated by vast agricultural tracts and the skyline of the City of Chicago, the third largest city and metropolitan area in the US.Chicago's growth arises from its strategic position connecting trade between the Mississippi River system and the Great Lakes (and since 1959, the Atlantic). It is also a major center of manufacturing, and the transportation and communications hub of the Midwest.Passed to the US as part of the Northwest Territory, Illinois was admitted as the 21st state in 1818. It is significant to two presidents: Abraham Lincoln, who launched his political career here; and Ronald Reagan, who was born and schooled here. State Capital: City of Springfield, Illinois.State Song: Illinois written by C.H. Chamberlain. The music was composed by Archibald Johnston.State Animal: White-tailed DeerState Bird: CardinalState Dance: Square DanceState Fish: BluegillState Flower: Blue VioletState Fossil: Tully MonsterState Insect: Monarch ButterflyState Mineral: FluoriteState Tree: White Oak (Quercus alba)State Prairie Grass: Big Bluestem