Biohazard Cleanup Near Gettysburg O'Fallon, IL

O'Fallon is a city in St. Clair County, Illinois, about 18 miles east of downtown St. Louis, and with 32,289 residents at the 2020 census it is the second-largest city in the Metro East region and Southern Illinois.

O'Fallon was founded in 1854 and named for Colonel John O'Fallon, a wealthy St. Louis gentleman; city lots were platted around a new Baltimore and Ohio Railroad depot and sold at public auction on May 18, 1854.

O'Fallon was incorporated as a village on January 27, 1874, and its citizens voted to switch to a city form of government on March 14, 1905.

German settlers were drawn to O'Fallon by its fertile farming land, and a post office opened the year after the town was founded.

O'Fallon has grown in every decennial census since its founding except 1930, when it lost exactly six residents.

The 2020 census counted 12,559 households in O'Fallon with a median age of 38.0 years, and Census Bureau survey data put the household count at about 12,800 in the early 2020s.

O'Fallon sits just 5 miles from Scott Air Force Base, and many residents work at the base in military or civil service jobs — the airplanes on the city's seal represent the base, while its pick and shovel honor the coal mines that powered the local economy for over 100 years.

Growth exploded after Interstate 64 was expanded in the 1990s, filling subdivisions such as Nolin Creek, Forest Hills, Thornbury Hill and Fairwood Hills, and more than half of O'Fallon's housing stock is relatively new.

Students attend O'Fallon Township High School, whose main campus is on South Smiley Street with a separate Milburn Campus for freshmen; the high school's blue and gold colors are also the colors of the city flag.

O'Fallon's parks include O'Fallon Community Park, Hesse Park, the Family Sports Park and Rock Springs Nature Park, which has a nature center, prairie, trails and a dog park, plus St. Ellen Mine Park on the site of an old coal mine.