a city in the USA, in the state of Illinois. Second among US cities in economic importance and population and the largest center of industry, commerce, transport, and finance west of the Appalachian Mountains. Situated on the southwestern end of Lake Michigan where the Chicago River meets the lake, at the beginning of the canalized waterway that extends from the Great Lakes to the Mississippi River. Area, 575 sq km. Population, 3.2 million (1975), 33 percent of whom are Negroes.
Chicago forms part of one of the largest conurbations in the USA. Called the Chicago-Northwestern Indiana Standard Consolidated Area, the metropolitan area includes Chicago and various cities in Illinois and Indiana, such as Gary, Hammond, and East Chicago. It covers an area of 9,000 sq km and has a population of 7.7 million (1975). In 1974 the economically active population totaled 3.3 million; 31 percent were employed in industry, 5 percent in construction, 7 percent in transport, 6 percent in finance, 39 percent in commerce and the service sector, and 12 percent in the civil service. Approximately two-thirds of those working in industry are employed in heavy industry, and more than one-tenth, in the food-processing industry.
Chicago’s location on the principal east-west arteries of the USA and at the junction of land and water routes has made it an important transportation center of the USA (more than 30 railroad lines converge at the city) and a major center of domestic air traffic. The Port of Chicago, which includes piers on Lake Michigan, is the largest port on the inland waterways of the USA, and it handled more than 50 million tons of freight in 1974.
Chicago is the center of US ferrous metallurgy; its steel-melting furnaces have a capacity of approximately 30 million tons. Leading products of the city include communication facilities, electronic equipment, electrical machinery, transportation equipment, agricultural machinery, and various types of equipment for industry, construction, and road building. The printing, chemical, petroleum-refining, garment, and furniture industries are well developed, as is the food-processing industry, which is dominated by flour milling and the production of canned meat. Heavy machine building and the metallurgical, petroleum-refining, and chemical industries are located primarily along Lake Michigan in southeast Chicago (near the port) and in the adjacent suburbs of Indian Harbor, Gary, and East Chicago. Machine building is most highly developed in the western section of the industrial complex, in such areas as Cicero.
Chicago is the most important market in the USA for wheat, maize, soybeans, and livestock, and its stock exchange is second in importance only to the New York Stock Exchange. The Chicago financial group is one of the major groups of finance capital in the USA. Capitalist monopolies dominate the city’s industry and commerce, with the firms International Harvester and Pullman playing a major role in machine building and the General Foods Corporation occupying a leading position in the food-processing industry. The country’s largest grain exchange is located in Chicago.
For a long period the area that is now Chicago belonged to the Indians. The city developed on the site of Fort Dearborn, a military post established in the early 19th century. In 1833 the settlement that grew up around the fort was incorporated as a city. The city’s rapid population growth, which was particularly marked after the completion of the Illinois-Michigan Canal in 1848 and a railroad line to the Atlantic Ocean in 1852, made Chicago the country’s largest city after New York by the end of the 19th century; it had 550 inhabitants in 1830, 4,500 in 1840, 109,000 in 1860, and 1,100,000 in 1890. In the 1840’s industry began to expand rapidly, and in 1893 an international fair, the World’s Columbian Exposition, was held in the city.
Chicago was an important center of the working-class and democratic movements. In 1870, sections of the First International were formed in the city. Notable events involving the Chicago proletariat in the late 19th century included the Haymarket Square Riot of 1886 and the Pullman strike of 1894. The trade union organization Industrial Workers of the World was founded in Chicago in 1905, and the Communist Party of the USA was founded in 1919. In 1937 police, in an incident known as the Memorial Day Massacre, fired on workers demonstrating against Republic Steel. In the 1960’s and 1970’s Chicago became a center of the civil rights movement, and during the American aggression in Vietnam (Vietnam War) massive antiwar demonstrations were held in the city.
Chicago, a city of sharp social contradictions and contrasts, is noted for its elegant lakefront; for its business center of huge skyscrapers, called the Loop, which is located near the place where the Chicago River meets Lake Michigan; and for its area of private residential buildings north of the Loop, known as the Gold Coast. The city is also renowned for its parks, its wide boulevards, and its drive that runs along the lakeshore. Alongside these attractions, however, are neglected slum areas and the ethnic ghettos of Chinatown and the Negro districts; in the west and southeast lie the industrial areas.
After the fire of 1871, which virtually destroyed the city, Chicago was completely rebuilt, and skyscrapers with metal skeletons were erected. The Chicago school of architecture, a precursor of the rational architecture of the 20th century, produced such structures as the second Leiter Building (now Sears and Roebuck; 1889–91, architect W. Le Baron Jenney), the Reliance Building (1890–94, architects D. H. Burnham and J. W. Root, assisted by C. B. Atwood), and the Carson Pirie Scott department store (1899–1900, architect L. Sullivan).
In the 20th century, rebuilding has been restricted to the construction of skyscrapers in the Loop, such as the Tribune Tower (1923–25, architects J. M. Howells and R. Hood); elegant complexes, such as the Civic Center (1963–65, architect J. Brown-son); and expressways that are incongruous with the city’s layout.
Chicago remains an important center of architectural design. Among its notable structures are F. L. Wright’s Robie House (1909), now part of the University of Chicago, and numerous buildings by L. Mies van der Rohe—including the Illinois Institute of Technology (1942–58), high-rise apartment buildings on Lake Shore Drive (1950–51), and the Commonwealth Promenade Apartments (1957). B. Goldberg designed the Marina City high-rise apartment buildings (1964), and the architectural firm of Skidmore, Owings, and Merrill designed the 100-story Hancock Building (1971) and the 109-story Sears Tower (1970–74), which, with a height of 442 m, is the world’s tallest building.
A major scientific and cultural center of the USA, Chicago is the location of such nationally important universities as the University of Chicago, Northwestern University, De Paul University, and the Illinois Institute of Technology. Museums include the Field Museum of Natural History and the Museum of Science and Industry. Other cultural and educational institutions include the Art Institute of Chicago, the John G. Shedd Aquarium, the Chicago Public Library, and the Shubert and Blackstone theaters.