Read about the geography and natural features, as well as the cities, highways and airports in Illinois. View the road maps, relief maps, and topographical maps of Illinois. - [Read more]
This is the Illinois state category. Illinois' capital city is Springfield, and its postal abbreviation is IL. Illinois entered the Union as the 21st state, on December 3, 1818. Illinois is the 24th largest state, with an area of 57,918 square miles. The state is located in north central USA, on the east bank of the Mississippi River. Illinois was explored first by the French in 1673, and ceded to the British in 1763. It was occupied by American troops during the American Revolution. The land is fairly level and is drained by many rivers flowing southwest to the Mississippi. Chicago, the state's largest city, is a transport center and a major Lake Michigan port.