Illinois (abbr.: IL or Ill.), state of the United States of America, in the Midwest, 145,934 km2, with 11.4 million inhabitants; capital city: Springfield. The state got its name from French settlers, who named it after the tribe of the Illini Indians living here at the time; in Algonqui spoken by those Indians, illini means “people” or “warriors.”
Except for the extreme south, the state belongs to the large flat prairie region of the Midwest. The highest point is Charles Mount (370 m), near the border with the state of Wisconsin, which is part of a group of hills in the northwest of the state. River bluffs run along the Wabash and Mississippi, and in southern Illinois are the Illinois Ozarks, a continuation of the Ozark Plateau. The state has about 500 rivers that partly flow into the Mississippi and its tributary Illinois (800 km). The Mississippi flows along the entire eastern border of Illinois. The climate is characterized by great extremes of heat and cold. Tornadoes are not an unknown phenomenon.
The average population density is 76 inhabitants. per km2. The largest metropolitan areas are Chicago, Springfield, Peoria, and Rockford; 85% of the population lives in the cities. See top cities in Illinois.
Its favorable location, fertile soil and mineral wealth has allowed Illinois to develop into one of the most economically important states in the country. The traditionally very important agriculture has as main products maize and soybeans; in addition, extensive livestock breeding (particularly pigs; meat industry) and floriculture (roses, carnations, gladiolus). The mining industry produces, among other things, coal, petroleum and fluorite.
Industry is the main livelihood. The industrial center is located in and around Chicago; in addition, there are extensive industrial complexes around the major cities (East St. Louis, Peoria, Rockford, Springfield and Decatur). The industry primarily includes mechanical engineering; furthermore petroleum refining, processing of agricultural products (meat, grain) and chemical, metal, food and electrical industry.
Among the most visited natural sites is Starved Rock with jagged limestone formations, 100 miles southwest of Chicago, Cahokia Mounds State Historic Site with Native American burial mounds, Apple River Canyon State Park, Dixon Springs State Park with more than 1,500 waterfalls, and Giant City State Park.
The area was originally inhabited by the Illini Indians; it was explored in 1673 by the French L. Jolliet and J. Marquette. The first French settlements by La Salle (commercial forts at later Peoria and Starved Rock) date from ten years later. Immigration started quite quickly. In 1763 the area became English, but during the Revolution it was conquered by the American pioneer GR Clark. After the peace of 1783, the state of Virginia, which had claims to the territory to the west, ceded it to the Union, and so in 1787 Illinois belonged to the northwestern territory that was then being organized. In 1800 it became part of the Indiana Territory, in 1809 it became a separate territory, in 1818 the 21st state of the Union. Much turmoil gave the issue of slavery, for which there was much sympathy, especially in the south of the state. However, an attempt to introduce slavery in 1824 failed. In 1833 the last Indian lands had been bought up and now, especially due to the better connections (canals, railways), a rapid revival began; in particular, many Germans and Irish entered the state.
Politically, Illinois was Democratic at first, then mostly Republican after 1856, though in 1858 the Republican nominee for senator, Abraham Lincoln, was defeated by his Democratic opponent S. Douglas. Despite southern sympathies in some parts, the state gave strong support to the Union in the Civil War in 1861. Very quickly after the war the revival started due to the great migration to the west. Chicago became the powerful center of commerce. After the depression in the 1930s, the state grew into one of the most important and wealthiest states in America.