Settlers originally named the city "Calhoun" after Senator and Vice President John C. Calhoun of South Carolina, but in 1832, after Calhoun fell out of favor, the city took its current name, derived from nearby Spring Creek.

Springfield's most famous historic resident was Abraham Lincoln, who lived in the city from 1837 until 1861, when he moved to the White House. He gave a particularly emotional farewell address upon leaving Springfield on February 11, 1861. The demands of the Civil War and his assassination in 1865 ensured that Lincoln would never return to Springfield alive, but his body was buried at Oak Ridge Cemetery in Springfield and now lies within the Lincoln Tomb.

Springfield's own Cozy Dog Drive-in claims to have been the first restaurant to serve corn dogs on a stick, on June 16, 1946. Though it took a little time to perfect the mounted rack that allows the hot dogs to be battered and fried vertically, the batter recipe has remained unchanged since 1946. The horseshoe sandwich, not well known outside of central Illinois, also originated in Springfield.

Springfield has a total area of 65.764 square miles (170.33 km²), of which 59.48 square miles (154.05 km²) or 90.44% is land and 6.284 square miles (16.28 km²) or 9.56% is water.

On August 15, 2020, Springfield's Route 66 MotorHeads Bar, Grill and Museum erected the world's largest Route 66 emblem. According to the Springfield State Journal-Register, the sign measures 32 by 32 feet and is attached to two 60-foot-tall poles that once carried a Stuckey's sign.

Springfield, a political and financial center of Union support, became a major hub of activity during the American Civil War. Illinois regiments trained there, the first ones under Ulysses S. Grant, who led his soldiers to a remarkable series of victories in 1861-62.

During the Civil War, the Illinois Governor's Mansion was home to Governor Richard Yates and his family. According to local legend, the mansion continues to host Yates' wife, Catherine, who allegedly makes her presence known in a variety of ways, including tampering with electronics and smoke alarms. The upstairs bedroom where her portrait hangs is said to be the most active room in the house.

Since 2002, Springfield has hosted the Route 66 Film Festival, which celebrates films routed in, based on, or taking part on the famous Route 66.

If you love to grab a bite to eat without having to get out of your car, you owe a debt of gratitude to Springfield. This very American concept has its roots in the city, where the Maid-Rite Sandwich Shop still operates what it says is the first drive-thru window in the country.

Although Legally Blonde 2: Red, White & Blonde is set in Washington, D.C., the film was shot at the Utah State Capitol in Salt Lake City, Utah, and the Illinois State Capitol in Springfield, Illinois. The supposed "aerial views" on Washington buildings were scale models built by the crew.