Illinois State University (ISU), founded in 1857, is the oldest public university in Illinois, United States; it is located in the town of Normal. ISU is considered a "national university" that grants a variety of doctoral degrees and strongly emphasizes research; it is also recognized as one of the top ten largest producers of teachers in the US according to the American Association of Colleges of Teacher Education. The ISU athletic teams are members of the Missouri Valley Conference and the Missouri Valley Football Conference and are known as the "Redbirds," in reference to the state bird, the cardinal.

ISU was founded as a training school for teachers in 1857, the same year Illinois' first Board of Education was convened and two years after the Free School Act was passed by the State Legislature. Among its supporters were judge and future Supreme Court Justice, David Davis and local businessman and land holder Jesse W. Fell whose friend, Abraham Lincoln, was the attorney hired by the Board of Education to draw up legal documents to secure the school's funding Founded as Illinois State Normal University, its name was reflective of its primary mission as a teacher training institution (at that time called a normal school). Classes were initially held in downtown Bloomington, occupying space in Major's Hall. It had previously been the site of Lincoln's "lost speech". The school moved to its current campus in 1860 in what was then the village of North Bloomington, which was chartered as "Normal" in 1865.

Illinois (ⁱ/ˌɪlɨˈnɔɪ/ IL-i-NOY) is the 25th most extensive and the 5th most populous of the 50 United States, and is often noted as a microcosm of the entire country. With Chicago in the northeast, small industrial cities and great agricultural productivity in central and northern Illinois, and natural resources like coal, timber, and petroleum in the south, Illinois has a broad economic base. Illinois is a major transportation hub. The Port of Chicago connects the state to other global ports from the Great Lakes, via the Saint Lawrence Seaway, to the Atlantic Ocean; as well as the Great Lakes to the Mississippi River, via the Illinois River. For decades, O'Hare International Airport has ranked as one of the world's busiest airports. Illinois has long had a reputation as a bellwether both in social and cultural terms and politics.

Although the state's largest population centers today are in northern Illinois, originally the state's population grew from south to north, with settlers arriving from Kentucky in the 1810s. In 1818, Illinois achieved statehood. Chicago was founded in the 1830s on the banks of the Chicago River, one of the few natural harbors on southern Lake Michigan. Railroads and John Deere's invention of the self-scouring steel plow turned Illinois' rich prairie into some of the world's most productive and valuable farmlands, attracting immigrant farmers from Germany and Sweden. By 1900, the growth of industrial jobs in the northern cities and coal mining in the central and southern areas attracted immigrants from Eastern and Southern Europe. Illinois was an important manufacturing center during both world wars. The Great Migration established a large community of African Americans in Chicago that created the city's famous jazz and blues cultures.

A state university system in the United States is a group of public universities supported by an individual state, or a similar entity such as the District of Columbia. These systems constitute the majority of public-funded universities in the country. Each state supports at least one such system.

Federal funded colleges and universities are limited to military personnel and government employees. Members of foreign militaries and governments also attend some schools. These schools include the United States military academies, Naval Postgraduate School, and military staff colleges.

A state university system normally means a single legal entity and administration, but may consist of several institutions, each with its own identity as a university. Some states—such as California and Texas—support more than one such system.

State universities get subsidies from their states. The amount of the subsidy varies from university to university and state to state, but the effect is to lower tuition costs below that of private universities. As more and more Americans attend college, and private tuition rates increase well beyond the rate of inflation, admission to state universities is becoming more and more competitive.