ILLINOIS, gli-nor or -noiz, the eighth State admitted into the Union, and since 1890 the third in population, is one of the North Central States of the United States. It is widely known as the "Prairie State." It lies between 87° and 35' and 91° and 40' W. longi tude, and between 36° and 59' and 42° and 30' N. latitude. By the enabling Act of Congress, by virtue of which the State was organized, its boundaries were fixed as follows: "Beginning at the mouth of the Wabash River, thence up the same, and with the line of Indiana, to the northwest corner of said State; thence east with the line of the same State to the middle of Lake Michigan; thence north along the middle of said lake, to north latitude 42 de grees 30 minutes; thence west to the middle of the Mississippi Rivet; and thence down along the middle of that river to its confluence with the Ohio River; and thence up the latter river along its northwestern shore, to the beginning.° Topography, etc.—Illinois is practically surrounded bywater. It is bounded on the northeast by ke Michigan, on the north by Wisconsin, on the east by Indiana, on the south by Kentucky and on the west by Iowa and Missouri. It is separated from the two last named States by the Mississippi River, from Indiana by the Wabash and Ohio, and from Kentucky by the Ohio. Illinois has a gross area of 56,665 square miles, but 622 square miles represent water surface. Its extreme length is 385 miles and its extreme breadth 218 miles. It ranks twenty-third in size among the States of the Union. With the ex ception of Georgia, its area is greater than that of any one of the original States of the Union. It comprises a territory larger than that of England, or of Belgium, Switzerland and Hol land combined. The largest county, McLean, has an area of 1,166 square miles, and the smallest, Putnam, an area of 176 square miles. With two exceptions — Louisiana and Dela ware—Illinois is the most level of the States. Its greatest elevation is 1,150 feet above the sea, and its mean elevation is 550 feet. The larger part of its surface consists of level or slightly undulating prairies, but a portion of the extreme northwestern part is hilly, and there are occasional bluffs upon the Illinois and Mississippi rivers. In the extreme south also there is a range of hills rising to a height of about 1,000 feet.
The soil consists of a rich black loam, or mold, underlaid by drift deposits, in many places of great depth, and varying from 10 to 200 feet. There are three sources of the soil in this State. The residuary soil, resulting
from the decay of the original rock layers, is the first. Before the visit of the first ice sheet the entire State was probably overlaid with thick layers of residuary soil. A second kind of soil came from the first ice sheet, which brought into the State great quantities of waste material from the regions around and beyond the lakes. This was left scattered over the State, but it soon weathered and with the addi tion of humus made a black and rich prairie soil. After the disappearance of the first ice sheet and the making of the waste material into soil, there was a thick deposit of loess, which covered not only the glacial soil but also the residuary soil. After thousands of years there was a second ice invasion which reached as far south and west as the line traced west and north from Paris. A second glacial layer of waste several feet thick was thus left upon the loess beds. Illinois consequently has soil whose source is the residuary rocks (the area being very limited), soil from the loess deposits and that from the last ice sheet in the northeastern counties. The soil of the river valleys is allu vial and is especially, fertile. The northern part of the State is especially well suited to the cul tivation of hay, the north and central parts to Indian corn, the east to oats and the southwest to wheat.
Rivers, etc.- The water courses flow gen erally from the north and northeast to the south and southwest. The principal river of the State, the Illinois, is formed by the junction in Grundy County, 40 miles southwest of Chicago, of the Kankakee and Des Plaines. The last-named river takes its rise in Wisconsin and flows in a southerly direction, while the headwaters of the Kankakee are in northern Indiana. The Illinois is navigable for 245 miles and is con nected by the Illinois and Michigan Canal with Lake Michigan. Other rivers in the State are the Sangamon, which flows in a westerly direc tion into the Illinois; the Kaskaskia, which flows in a southwesterly direction and empties into the Mississippi near the ancient village of Kaskaskia, the first capital of the State; Rock River, which flows in a southwesterly direction from Wisconsin and empties into the Missis sippi not far from the city of Rock Island; the Little Wabash and the Embarras, which flow into the Wabash in the southeastern part of the State; and the Vermilion and the Fox, which are tributaries of the Illinois.