Belleville. 1 City (1990 pop. 42,785), seat of St. Clair co., SW Ill.; inc. 1819. Located in a coal-mining area, Belleville also has farm-related industries and printing, food processing, and a large variety of manufactures, including mining equipment, shoes, iron products, and building materials. Scott Air Force Base (est. 1917 for flight instruction) lies to the northeast; near it is the large MidAmerica airport. 2 Town (1990 pop. 34,213), Essex co., NE N.J., on the Passaic River; settled c.1680, set off from Newark 1839, inc. 1910. Electrical and optical equipment, gloves, and precision instruments are among its manufactures. John Stevens's boat, built there in 1798 for the run to New York, contained one of the country's first steam engines.