Illinois, the seventeenth in area of the United States, but the third in population, extends from Wisconsin and Lake Michigan on the N. and NE. to the junction of the Ohio and Mississippi rivers at the extreme SW.—a distance of nearly 400 miles. It is bounded on the E. by the state of Indiana, from which it is partly separated by the Wabash River; on the S. it is separated from Kentucky by the Ohio; and on the W. the Mississippi flows between it and the states of Iowa and Missouri. The area is 56,650 sq. m., or nearly that of England and Wales.
The surface of Illinois is the most level of any state in the Union, except Delaware and Louisiana; and its wide grassy plains, though broken by numerous streams fringed with belts of fine timber, have gained for it the name of the Prairie State. The drainage is towards the south-west, through streams which flow into the Mississippi. The Illinois River, the largest in the state to which it gives name, is formed by the union of two streams in the north-east of the state, about 45 miles south-west of Lake Michigan, and has a south-west course of about 500 miles in all, joining the Mississippi 20 miles above the mouth of the Missouri. The fertile soil—a heavy black loam—with a favourable climate, makes this the richest agricultural state in the Union; and Illinois ranks first for the production of corn, cattle, hogs, and horses.
The annual value of the principal crops—maize, oats, hay, wheat, potatoes, rye, barley, buckwheat, flax, tobacco—is well over $150,000,000. There are extensive vineyards in the state, and good wine is made. Much fruit is raised, especially for the markets of Chicago. Forests still cover a large area of the land. Honey and wax are obtained on a large scale. There are 1,500,000 horses and mules, over 3,000,000 cattle, and 1,000,000 sheep in the state.
The mineral output of Illinois, especially of bituminous coal, is also large; the state ranks next to Pennsylvania in this respect. Nearly a fifth of the entire coalfield of the United States is found in this state; and though some three-fourths of the coal is found in the Joliet region in the north-east, there are some 900 collieries in about fifty separate counties of the state. The annual output reaches 15,000,000 tons, and the industry employs 30,000 persons. There are brine-springs in the south of the state. Iron and zinc are also worked; and other minerals are lead, limestone, salt, and fluor-spar, the last found near Roseclare.
The position of Illinois presents unusual facilities for commerce. It has 400 miles of navigable rivers; a waterway to the Atlantic through the great lakes; and the drainage-canal (1900) from the Chicago River to the Desplaines connects Chicago with the Mississippi River. Illinois has more railroads than any other state—10,776 miles in 1897. The trade of the state centres in Chicago, and in the article on that city statistics are given, as well as some indication of the leading manufactures. Of these last the principal are connected with agriculture.
The state is divided into 102 counties. The governor and most of the other state officers are elected for four years, the judges of the supreme court for nine. The legislature meets biennially; and to the lower house each district returns three members, cumulative voting being permitted in order to provide for the representation of minorities. Twenty representatives are sent to the Federal congress. The provisions for education are liberal. The state maintains two normal schools, an agricultural college, and an industrial university; and besides these there are many other colleges and universities. A compulsory educational law is in force, which requires children between the ages of seven and fourteen to attend for at least sixteen weeks in the year some public day school, or some private school teaching the branches commonly taught in the public schools. The most important educational institutions, including the magnificently endowed Chicago University, are in and about Chicago (q.v.). Thirty higher institutions have 700 teachers and over 10,000 pupils. Over 25,000 elementary teachers instruct 800,000 pupils. The state charitable institutions include four hospitals for the insane, at Elgin, Kankakee, Jacksonville, and Anna; an institution for the deaf and dumb, and another for the blind at Jacksonville; an asylum for the feeble-minded at Lincoln; a home for the orphans of soldiers at Normal; and eye and ear infirmary at Chicago; a reform school for boys at Pontiac; and a soldiers' and sailors' home at Quincy. The 475,000 Roman Catholics in the state have an archbishop and three bishops.
Formerly a part of the North-west Territory, Illinois was organised as a territory in 1809, and admitted as a state on 3d December 1818. While the Federal law at that date made a population of 40,000 a condition of admission, it is well established that the actual population of Illinois was then but 34,620. In 1830 the population numbered 157,445; in 1850, 851,470; in 1870, 2,539,891; in 1880, 3,077,871; and in 1890, 3,826,351. Chicago is by far the largest city of Illinois; its limits embrace more than a fourth of the entire population of the state. Peoria, Quincy, Springfield (the capital), and Rockford rank next in population. Important events in the history of Illinois have been the Indian wars of the territorial period, the Black Hawk war of 1832, and the Mormon (q.v.) troubles in 1840-44. The state raised six regiments for the Mexican war, and during the civil war contributed 259,092 men to the Union armies, of whom over 29,000 were killed in action or died of wounds or disease. At Springfield Abraham Lincoln lived before he was elected president, and there he is buried. See S. Breese, Early History of Illinois (Chicago, 1884); J. Moses, Illinois, Historical and Statistical (Chicago, 1889).