The Quad Cities, in order of descending population, are:
Before World War II, the area was known as the “Tri-Cities“, and included only Davenport, Rock Island, and Moline. With the growth of Rock Island County, East Moline was eventually given “equal status,” and the region became known as the “Quad Cities” during the early 1960s.
By the 1970s, Bettendorf had grown such that many people in the community openly discussed the adoption of the name “Quint Cities“. However, by this time, the name “Quad Cities” had become known well beyond the area, and Quint Cities never caught on. As Bettendorf passed East Moline in size, it became one of the Quad Cities—a name that is now technically a misnomer, as the area includes five cities each with a population of over 20,000.