Illinois is the most populated and diverse of the Midwestern states. It has the fifth largest population in the United States and was the 21st state to be admitted into the union. Illinois has abundant resources such as coal, oil and wood in the south and a great agricultural base in the central and western areas. The Port of Chicago connects the Mississippi River to the Great Lakes through the Illinois River, helping to make Illinois one of the most successful industrial and agricultural regions. Illinois is famous for being the most average of the states demographically; a microcosm of what it means to be an American. Learn more about some of Illinois’ largest and well-known cities.