Alton, city, Madison county, southwesternIllinois, U.S. Part of theSt. Louis, Missouri,metropolitan area, Alton lies on theMississippi River (bridged) near itsconfluence with theMissouri River.

The city was named for a son of Colonel Rufus Easton, a St. Louis land speculator who laid out thecommunity in 1818 as aferry site. It quickly developed into a busy river port. Illinois’s first statepenitentiary (the building is now gone) opened there in 1833; the prison housed Confederate soldiers during theAmerican Civil War. Ammunition manufacture began in Alton in the 1890s and remains an important part of the city’s economy. Other manufactures includesteel, petroleum products, and machinery for producing glass. Grain, coal, and petroleum products are shipped from the port. Casino gambling also contributes to the economy.

TheSouthern Illinois University School of Dental Medicine is located in Alton; Lewis and Clark Community College was established (1970) on the campus of the former Monticello College (founded 1838) in nearby Godfrey. Alton features a museum of local history and art (founded 1971). A monument memorializes the abolitionist newspaper editorElijah P. Lovejoy, who was killed in Alton by a proslavery mob in 1837. The site of the finalLincoln-Douglas debate in 1858 iscommemorated by life-size bronze statues ofAbraham Lincoln andStephen A. Douglas. There is also a life-size statue of Alton native Robert Pershing Wadlow (1918–40), who, at nearly 9 feet (2.7 metres) tall, was the world’s tallest man. ThePiasa bird, described byJacques Marquette in 1673 as a birdlike monster etched in the bluffs on the Mississippi, is a famous local legend; a depiction has been repainted on the bluffs. Located nearby are Two Rivers National Wildlife Refuge (part of theMark Twain National Wildlife Refuge Complex) and Pere Marquette State Park. Inc. town, 1833; city, 1837. Pop. (2000) 30,496; (2010) 27,865.