Route 6 crosses the Mississippi River at the Quad Cities of Iowa and Illinois. Its original path (indicated by the orange dashed line) brought it into Davenport from the West and to the river in Davenport's downtown area.  It then crossed the river on the Government Bridge to Rock Island, Illinois, touching the western end of the island of Rock Island in the process. Then it headed east past Augustana College, through downtown Moline, and into East Moline (one of the five Quad Cities!).  From there it took a stair-step path toward Geneseo, the next town off the map to the east.

In the late 1930s, the highway was significantly rerouted, beginning with the completion of the Iowa Memorial Bridge in November 1935, which connects Moline with Bettendorf.  This project, completed with Federal depression-era funds, included the building of two new four-lane roads, a by-pass around Davenport on Kimberly Road and a new road connecting downtown Moline with the Quad City Airport.  This latter segment included a new bridge over the Rock River, completed in 1938.  Finally, a new two-lane paved road, extending eastward from the airport, was constructed south of the Rock River.  (Map drawn by A-me Li, of Augustana College.)

Early Route 6 crossed the Mississippi on the Government Bridge, a double-decker designed and built by Ralph Modjeski in 1896.  It was the third successor to the first railroad bridge to cross the Mississippi, completed in 1856.  It's upper deck carries a pair of railroad tracks, originally for the Rock Island Lines and now for the Iowa Interstate Railroad. This lower deck accomodates bicycles, pedestrians, and motor vehicles. Until 1940, the lower deck also accomodated streetcars, as suggested by the tracks shown in this 1920s photograph. A pictorial history of the bridges at this location can be found at:  http://www.riveraction.org/node/28