The Quad Cities is a region of five cities along the Mississippi River. Originally made up of Davenport, Iowa, and Rock Island, Moline, and East Moline in  Illinois. Bettendorf, Iowa was added in the 1970s but the name Quint Cities never caught on. It became a center of manufacturing, particularly of tractors and other agricultural equipment. The first railroad bridge across the Mississippi was built between Davenport and Rock Island in 1856 by the Rock Island Railroad Co.