PEORIA, a city, port of entry, and the county-seat of Peoria county, Illinois, U.S.A., in the north central part of the state, on the lower end of Lake Peoria, an expansion of the Illinois river, and about 150 m. S. W. of Chicago Pop. (1900) 56,100, (1910) 66,950. It is served by 13 railways, of which the most important are the Chicago, Burlington & Quincy, the Chicago, Rock Island & Pacific, the Chicago & Alton, the Illinois Central, the Cleveland, Cincinnati, Chicago & St Louis, and the Chicago & North-Western. The Illinois river is navigable to its mouth, and at La Salle, above Peoria, connects with the Illinois & Michigan Canal extending to Chicago. The river is spanned at Peoria by two railway bridges and a wagon bridge. The residential portion of the city is situated on bluffs overlooking Lake Peoria, and the business streets lie on the plain between these elevations and the water front. The park system includes more than 400 acres; Bradley Park (140 acres), the largest, was given to the city by Mrs Lydia Moss Bradley (1816-1908) and was named in her honour. On a bluff north-east of the city is Glen Oak Park (103 acres), modelled after Forest Park, St Louis, Missouri; in the south-western part of the city is Madison Park (88 acres); and in the lower part of the city is South Park (10 acres). In the Court House Square there are two monuments in honour of the Federal soldiers and sailors of Peoria county who perished in the Civil War, in Springdale Cemetery there are two similar memorials, one of which (a large granite boulder) is in memory of the unknown dead; and in the same cemetery there is a monument erected by the state (1906) to mark the grave of Thomas Ford (d. 1851), governor of Illinois in 1842-1846. Among the principal public buildings and institutions are the Peoria Public Library founded in 1855, the City Hall, the Court House, the Federal building, St Mary's Cathedral, the Bradley Polytechnic Institute (affiliated with the university of Chicago), founded in 1896 by Mrs Lydia Moss Bradley, who gave it an endowment of $2,000,000; Spalding Institute, founded through the efforts of John L. Spalding (b. 1840), who was Bishop of the Roman Catholic diocese of Peoria in 1877-1908, an Evangelical Lutheran Orphans' Home (1902), an Industrial School for girls (1892), Cottage Hospital (1876), St Francis Hospital (1875), a Florence Crittenton Home (1902), a Home for the Friendless (1876), and a House of the Good Shepherd (1891), and the Guyer Memorial (1889), St Joseph's (1892), and John C. Proctor homes for the aged and infirm (1907). At Bartonville, a suburb, there is a state hospital for the incurable insane.

In 1900 and in 1905 Peoria ranked second among the cities of Illinois in the value of its manufactures. The invested capital amounted in 1905 to $22,243,821, and the factory products were valued at $60,920,411. The principal industry is the manufacture of distilled liquors, which were valued in 1905 at $42,170,815. Other important manufactures are agricultural implements ($2,309,962), slaughter-house and meat-packing products ($1,480,398), glucose, cooperage ($1,287,742), malt liquors ($887,570), foundry and machine-shop products, strawboard, automobiles, brick and stone, and flour and grist mill products. Peoria is also an important shipping point for grain and coal.

Peoria was named from one of the five tribes of the Illinois Indians. In 1680 La Salle, the explorer, built Fort Crèvecœur, on the lake shore bluffs, opposite the present city; this fort, however, was destroyed and deserted in the same year by La Salle's followers after he had set out to return to Fort Frontenac. There is evidence that a French mission was established on or near the site of Peoria as early as 1711; and certainly by 1725 a settlement, known as Peoria, and composed of French and “breed” traders, trappers and farmers, had been established about 1½ m. above the foot of the lake, on its west shore. This village was practically deserted during the later years (1781-1783) of the War of Independence, and when its inhabitants returned after the peace they settled in a village which had been established about 1778, on the present site of Peoria, by Jean Baptiste Maillet (d. 1801), and was at first called La Ville de Maillet. It is probable that Jean Baptiste Point de Saible, believed to have been a Santo Domingan negro, and jocularly spoken of “as the first white settler in Chicago,” lived in the “old village” of Peoria as early as 1773—or six years before he settled on the present site of Chicago—and again about 1783. In November 1812 about half of the town was burned by a company of Illinois militia who had been sent thither to build a fort, and whose captain asserted that his boats had been fired upon at night by the villagers. In the following year a fort, named Fort Clark in honour of George Rogers Clark, was erected on the site of the old village; it was evacuated in 1818, and soon afterwards was burned by the Indians. After the town was burned there was no serious attempt to rebuild until 1819. Peoria was incorporated as a town in 1835 and was chartered as a city in 1845. In 1900 North Peoria was annexed.

See David McCulloch, Early Days of Peoria and Chicago, an address read before the Chicago Historical Society in 1904, and published by that society, (n.d.), and “Old Peoria,” by the same author, in publication No. 6 of the Illinois State Historical Society Transactions (Springfield, Ill. 1901); also Historical Encyclopaedia of Illinois (Chicago, 1900), ed. by Newton Bateman and Paul Selby; History of Peoria County, Ill. (Chicago, 1880); and C. Ballance, History of Peoria (Peoria, 1870).