Edwardsville was incorporated in 1818. The first European-American settler was Thomas Kirkpatrick, who came in 1805, laid out a community, and served as the Justice of the Peace. He named the community after his friend Ninian Edwards, then territorial governor of Illinois. (Illinois did not become a state until 1818.) The Edwards Trace, a key trail in the settlement of Central Illinois, used Edwardsville as a northward launching point.
In 1868 The Bank of Edwardsville was founded. It is still a functioning regional bank. 
In 1890, St. Louis industrialist N.O. Nelson chose a tract of land just south of Edwardsville to build plumbing factories. He also built a model workers' cooperative village called Leclaire. He offered workers fair wages with reasonable working hours and a share of the profits. He named the village in honor of the French economist Edme-Jean Leclaire. The village also provided educational and recreational opportunities and made it financially possible for anyone to own his own home. Unlike company towns such as Pullman near Chicago, the welfare and quality of life for the workers and their families was a major concern.
In 1934, the Village of Leclaire was incorporated into the City of Edwardsville. The area has a lake and park, baseball field, and the Edwardsville Children's Museum in the former Leclaire schoolhouse. Several Nelson factory buildings were renovated and adapted for use as the historic N. O. Nelson Campus of Lewis and Clark Community College. The recognized Historic District has been listed on the National Register of Historic Places.
Each year on the third Sunday in October, the Friends of Leclaire host the annual Leclaire Parkfest with food, live heritage music, historic displays & tours, artisans, children's activities, a book sale, and more.
In 1983, Edwardsville’s historic Saint Louis Street was also listed on the National Register of Historic Places. Dating back to 1809, this Historic District has a mile-long visual landscape. More than 50 historic homes date from the middle 19th century to early 20th century. The protection and preservation of Saint Louis Street is overseen by the Historic Saint Louis Street Association.
Five Illinois governors came from Edwardsville: namesake Ninian Edwards, who became a territorial governor in 1809 and later served as governor from 1826–1830; Edward Coles, elected in 1822 and a strong opponent of slavery; John Reynolds, governor from 1830 to 1834; Thomas Ford, governor from 1842–1846; and Charles Deneen, governor from 1909 to 1913.
Former president Abraham Lincoln was in Edwardsville twice, as an attorney in the 1814 courthouse and a speaker outside the 1857 courthouse on Sept. 11, 1858. The present county courthouse, a square, four-story neoclassical structure of white marble that rises to six stories at the back section, was constructed from 1913-15.
|City of Edwardsville|
Downtown Edwardsville with the Madison County Administration Building in the background
Location of Edwardsville in Madison County, Illinois.
Location of Illinois in the United States
|Coordinates: 38°48′14″N 89°57′30″WCoordinates: 38°48′14″N 89°57′30″W|
|Former seat||name="CenPopGazetteer2016">"2016 U.S. Gazetteer Files". United States Census Bureau. Retrieved Jun 29, 2017.</ref>|
|• Total||53.01 km2 (20.47 sq mi)|
|• Land||51.44 km2 (19.86 sq mi)|
|• Water||1.57 km2 (0.61 sq mi)|
| • Estimate
|• Density||487.41/km2 (1,262.39/sq mi)|
|Time zone||UTC−6 (CST)|
|• Summer (DST)||UTC−5 (CDT)|