ILLINOIS, one of the United States of America, extending from 36° 56' to 42° 30' n. lat., and 35' to 91° 40' w. long., being 388 m. long, and 212 wide; containing an area i of 55,405 sq.m., or 35,459,200 acres. It is bounded n. by Wisconsin; e. by lake Michi gan, and the state of Indiana, from which it is partly separated by the Wabash river; s. by the converging rivers Mississippi and Ohio, which separate it from Missouri and Kentucky; and w. by the Mississippi, which separates it from Missouri and Iowa. The state is divided into 102 counties; the capital is Springfield, near the center of the state, and the most important towns are Chicago, the principal port on lake Michigan, Galena and Alton on the Mississippi, and Cairo, at the southern terminus of the Central rail way, and the confluence of the Ohio and Mississippi rivers. Tlie population of the state has increased with marvelous rapidity. In 1810 it was 12,282; in 1820, 53,211; in 1830, 157,445; in 1840, 476,183; in 1850, 851,470; in 1860, 1,711,753; and in 1870, 2,511, 096. More than half the people of Illinois were born in other states or foreign countries, a large number being Irish and Germans. In 1850 there were but 707 paupers in a population of 831.470. The state of Illinois is generally level, having few hills and no mountains. The lowest portion is but 340 ft., and the highest only 1,150 ft., above the gulf of Mexico. It is nearly covered by fertile prairies; while river bottoms, with a soil of vegetable mold 40 ft. in depth, have produced heavy crops of maize for many successive years without manuring. The country is so level that the canal which unit•s lake Michigan with Illinois river and the Mississippi is fed by water pumped from the lake to a height of 12 feet. The principal rivers, besides those which form the bounda
ries, are the Illinois and Rock rivers, and their tributaries. The whole state is of lime stone formation, with rich lead deposits in the n.w., and a large portion of the great bituminous coal formation, 375 m. long and 200 wide, lying in this and tlie adjoining slates. The climate is mild, with an average of 77° Fahr. in summer, and 83i° in winter, but ranging from below to above zero; it is also healthy, except in swamp lands or river-bottoms, which are subject to fever and ague and bilious diseases. The productions arc wheat, maize, tobacco, cattle, hogs, apples, pears, peaches, grapes, etc. There were in 1865, 3,1570n. of railway in operation: in 1875 the mileage bad increased to 6.742 miles.
In 1870 Illinois contained 11,050 public schools, 6 universities, and 779 other schools. In the same year it produced 30,128.405 bush. of wheat, 120,921,395 bush. of Indian corn, and 42,780,851 bush. of oats. In 1830 the Mormons built the city of :Cativo°, on the Mississippi; but in 1844 their prophet, Joseph Smith, was killed by a mob; and his followers, 20,000 in number, made their exodus across the plains to the territory of 1:tah.—Illinois was first explored by La Salle, and the French missionaries and Indian trailers, who formed the earliest settlement at Kaskaskia, in 1673. Ceded by France to Great Britain. and then to the I.Tniied States, it remained a portion of the North-west territmy until its organizat:tm as a state, with a governor and legislature, in 1818.