the question of their connection with the people who erected the great truncated pyramidal earth mounds in the Mississippi bottoms, in the western part of the State.
The Illinois came early into relations with La Salle (1670-82) and the French traders. Through the influence of the Trappist monks these tribes were held loyal to the French in their wars with the neighboring tribes and afterwards with the English.
At the close of the Revolution the United States had great difficulty in subduing the Indians of this area. They now number 172, and are situated on a reservation in the Indian Territory.
ILLINOIS. ‘The Prairie State.’ A north-central State of the United States, lying between latitudes 36° 59′ and 42° 30′ N., and longitudes 87° 35′ and 91° 40′ W. It is bounded on the north by Wisconsin, on the northeast by Lake Michigan, on the east by Indiana, on the south by the Ohio River, separating it from Kentucky, and on the west by the Mississippi, flowing between it and Missouri and Iowa. Its greatest length is 385 miles; extreme width, 218 miles. Area, 56,650 square miles, of which 650 miles are water.
Topography. The whole State lies within the great prairie region, and has the physical appearance of a broad plain sloping slightly toward the south and southwest. After Louisiana and Delaware, it is the most level State in the Union. The surface of the plain, however, is not so monotonous as it appears on the map, being broken by minor undulations in a series of low hills and broad hollows. In the extreme northwest there are hills rising to an altitude of more than 800 feet, but the average elevations range from 600 feet in the north to 300 feet in the south. The elevation of Chicago is 582 feet. With the Ohio, Mississippi, and Lake Michigan on its borders, the State is well favored as to navigable waterways. The minor streams, with the exception of a few in the northeastern part, flow into the Wabash, Ohio, and Mississippi. The largest of these, the Illinois, has a course of nearly 500 miles, and can be ascended by small boats for a distance of 250 miles from its mouth. It drains central Illinois, receiving as affluents the Kankakee, Des Plaines, Fox, Vermilion, Mackinaw, Spoon, and Sangamon. Among the other important rivers are Rock River in the north, and the Kaskaskia, Big Muddy, Little Wabash, and Embarras in the south. Lake Peoria, in the central part of the State, is formed by a widening of the Illinois River.
Flora and Fauna. See paragraphs on these topics under United States.
Climate and Soil. The climate is typically temperate, the mean annual temperature ranging from 47° to 54° F. The winters are somewhat severe owing to the northerly winds, which have an unobstructed sweep over the prairies. Vegetation starts in April, and frosts occur about the middle of September. The average annual rainfall is thirty-eight inches. The soil consists of a rich, warm loam almost free from pebbles, and is mostly of glacial origin. An underlying stratum of hard clay prevents the seepage of moisture. On the river bluffs in the western part a fine, sandy deposit, called loess, occurs quite commonly, while the bottom lands have a surface of alluvial silt. The soils are remarkably fertile and require little artificial preparation to fit them for the growth of cereals.
Geology and Mineral Resources. During the Glacial period the area of Illinois was overrun by the northern ice sheet, which spread out a mantle of drift over the surface, burying the preëxistent topography. Only where the rivers have eroded their channels through this glacial material do the underlying formations outcrop. Silurian strata predominate in the northern part, and Devonian and Carboniferous in the central and southern parts. The coal-fields cover an area of 37,000 square miles; the number of seams varies from 7 to 12, with a thickness of 2 to 8 feet. The coal is bituminous, of Carboniferous age, and is best adapted for steaming. The most productive mines are located in Sangamon, Saint Clair, Vermilion, Macoupin, La Salle, Grundy, Williamson, and Bureau counties.
Mining. This industry is of little importance when compared with agriculture and manufacturing. Nevertheless, the production of bituminous coal has assumed enormous proportions. Illinois ranks second among the States in the amount of coal mined, and the output amounts to nearly 10 per cent. of the total for the country. The value of the annual output has increased from $10,000,000 in 1886 to $28,163,937 in 1901. Limestone is extensively quarried, the product being used for building and road-making purposes. The value of the annual output for the last decade has averaged about $2,000,000. Both of the above products are procured from a number of widely scattered points. The discovery and the mining of lead in the northwest corner of the State played an important part in the early settlement of the commonwealth. It is still mined to a limited extent. Some zinc is also mined in the northern part of the State. Fine clay and other commercial clays are mined, and the manufacturing of lime and of cement are well-established industries. The mineral waters of the State are also of considerable commercial value.
Fisheries. Many of the streams of the State abound in fish, which, though of little importance compared with the total food-supply, are yet worthy of consideration. German carp and buffalo-fish are commercially of most importance. Twenty shipping points on the Illinois River report the total value of fish caught for the year 1899 as $362,000. The protection and fostering of the fishing resources of the State are placed under the supervision of a State board of fish commissioners.
Agriculture. For several years following 1870 Illinois exceeded all other States in the per cent. of its farm area, in the per cent. of farm land improved, and the acreage in crops, and at the end of the century was exceeded in these respects by only one State—Iowa. According to the census of 1900, 91.5 per cent. of the land area was included in farms, of which 84.5 per cent. was improved, each of these percents, being the largest given in any Illinois census. In the greater part of the State the soil is a black loam of great fertility. The average size of farms decreased gradually until 1880; since then it has remained almost constant, being 124 acres in 1900. The per cent. of tenant-operated farms is rapidly increasing, amounting in 1900 to 39 per cent. of the total number. The share system of renting is most common. The products raised are of great variety, but corn has always
