Springfield is a city located in Sangamon County Illinois. It is also the county seat of Sangamon County. With a 2020 population of 113,010, it is the 6th largest city in Illinois and the 266th largest city in the United States . Springfield is currently declining at a rate of -0.54% annually and its population has decreased by -2.79% since the most recent census, which recorded a population of 116,250 in 2010. Springfield reached it's highest population of in . Spanning over 67 miles, Springfield has a population density of 1,854 people per square mile.
The average household income in Springfield is $77,473 with a poverty rate of 18.62%. The median rental costs in recent years comes to $805 per month, and the median house value is $133,400. The median age in Springfield is 39.4 years, 37 years for males, and 41.4 years for females.