a city of the state of Illinois, North America, situated on S.W. shore of Lake Michigan, at the mouth of the Chicago river. Lat. 42. 52. 20. N.; Long. 87. 35. W. Chicago is the most remarkable city in the states for the rapidity of its increase. In 1830 it was a mere trading station, and in 1840 had only 4470 inhabitants. In 1850 these had increased to 27,620, and in 1853 amounted to no less than 60,652. The city borders on a rich and beautiful prairie extending in different directions for many miles, finely diversified by groves and strips of timber, gardens, and villas. Though the site is low and level, being only a few feet above the lake, there are no marshes or wet lands; and the agitated waters of the lake ensure a salubrious atmosphere. The river Chicago consists of two branches, which unite about two miles from its mouth, forming an extensive and commodious harbour. The city extends along the shore of the lake for about a mile, and inland beyond the bifurcations of the river. The bar at the entrance has been much reduced, and piers have been erected to prevent the accumulation of sand, so that the depth is now sufficient for the largest lake craft and steamers. Chicago is the natural entrepot for the trade between the flourishing state of Illinois and the vast regions watered by the great lakes; and by means of an extensive system of canal and railway communication its commerce reaches from the Atlantic to the Mississippi. Of this system the most important features are—the Illinois and Michigan canal 100 miles in length, extending from the lake to the Illinois river at La Salle, and forming an outlet for the rich products of Kentucky, Missouri, Iowa, and Illinois; two lines of railroad round the bend of lake Michigan, thence continuous to the sea-board at Boston and New York, uniting also with the Indiana and Ohio railroads; lines to the Mississippi river at Galena, Rock Island, Quincy, Alton, Cairo, &c. There are 12 main trunk railways, 2646 miles in length, already in operation or to be completed by 1856, terminating at Chicago, and nearly each trunk has one or more branches; these are, the Michigan Central to Detroit, 208 m.; Michigan Southern to Toledo, 245 m.; Chicago and Fort Wayne, 180 m.; Illinois Central to Cairo, 351 m.; Chicago and Mississippi to Alton, 280 m.; Chicago, Aurora, and Central Military Tract to Quincy, 220 m.; Chicago and St Charles Air Line to Galena, 160 m.; Chicago and Galena to Dubuque, 200 m.; Illinois and Wisconsin to Fond du Lac, 180 m.; Chicago and Rock Island, 180 m.; Chicago and Cincinnati, 280 m.; Lake Shore to Milwaukee, 90 m. In 1842 the value of property in Chicago was assessed at £2,325,240, and in 1852 at £12,035,037. The arrivals of vessels at this port during 1852 were, 366 paddle and 181 screw-steamers, 20 barques, 257 brigs, and 1172 schooners, with an aggregate burden of 545,491 tons. Chicago in 1853 had 7627 dwelling-houses, 1184 stores and places of business, 54 schools, 61 churches, and 196 manufactories.