Springfield is the third and current capital of the US state of Illinois

Illinois

Illinois is the fifth-most populous state of the United States of America, and is often noted for being a microcosm of the entire country. With Chicago in the northeast, small industrial cities and great agricultural productivity in central and northern Illinois, and natural resources like coal,...

 and the county seat of Sangamon County

Sangamon County, Illinois

Sangamon County is a county located in the U.S. state of Illinois. According to the 2010 census, it has a population of 197,465, which is an increase of 4.5% from 188,951 in 2000...

 with a population of 117,400 (U.S. Bureau of the Census, 2010), making it the sixth most populated city in the state and the second most populated Illinois city outside of the Chicago Metropolitan Area. Just over 208,000 residents live in the Springfield Metropolitan Statistical Area

Springfield, Illinois metropolitan area

The Springfield Metropolitan Statistical Area, as defined by the United States Census Bureau, is an area consisting of two counties in Central Illinois, anchored by the city of Springfield...

, which includes Sangamon County and adjacent Menard County.