The city is a significant port for both domestic and international trade. Great Lakes freighters and river barges deliver bulk commodities such as iron ore, limestone, coal, chemicals, petroleum, and grain. Some of this freight is destined for processing plants in the heavily industrialized Calumet River area. Foreign vessels arrive via the Saint Lawrence Seaway, bringing products such as automobiles, steel, fish, and alcoholic beverages. The boats depart carrying machinery, farm equipment, hides, and lumber, as well as a variety of food products.
Manufacturing employs about one-fifth of the metropolitan area's workers.
Chicago's largest employer is the food products industry, followed by the printing and publishing, metal fabrication, electronic equipment, chemical, machinery, and transportation-equipment industries. The manufacture of furniture and agricultural implements has declined in importance in recent decades. Chicago is one of the nation's leading producers of steel, metalware, confectionery, surgical appliances, railroad equipment, soap, paint, cosmetics, cans, industrial machinery, printed materials, and sporting goods. Chicago contains the headquarters of numerous corporations and is an important wholesale market for grain, machine tools, produce, fish, and flowers. The Chicago Board of Trade and the Chicago Mercantile Exchange are among the world's largest commodities markets and have led in the development of futures trading and related concepts.