Moline, city, Rock Island County, northwestern Illinois, on the Mississippi River; settled 1832, incorporated as a city 1872. It forms the Quad Cities with Rock Island, in Illinois, and Davenport and Bettendorf, in Iowa. Agricultural equipment, its major product, has been made here since 1847. Heavy machinery, foundry items, machine tools, and elevators are also produced. The community grew in the 1840s as a flour-milling and sawmilling center; its name is probably derived from the French moulin (“mill”). Population 45,709 (1980); 43,202 (1990); 43,768 (2000); 42,892 (2005 estimate).