Macomb, city, seat of McDonough County, western Illinois, in a fertile farm area; incorporated as a city 1857. It is the seat of Western Illinois University (1889) and a junior college. It is most noted for its pottery, fashioned from the rich clay found here. Other manufactures include roller bearings, plastic products, and insulating porcelain. Argyle Lake State Park is nearby. The community was founded in 1829. It is named for General Alexander Macomb, a prominent American officer in the War of 1812. Population 19,863 (1980); 19,952 (1990); 18,558 (2000).
