|Carries||2 lanes of roadway
2 rail lines
|Locale||Davenport, Iowa and Rock Island Arsenal, Illinois|
|Maintained by||Federal government of the United States|
|Design||two riveted Pratt trusses
five riveted Baltimore trusses
one pin-connected Baltimore swing truss
|Total length||1,608 feet (490 m)|
|Width||27 feet (8 m)|
|Longest span||365 feet (111 m) (swing); longest fixed spans 258 feet (79 m)|
|Number of spans||8|
|Constructed by||U.S. Army|
The Government Bridge, or Arsenal Bridge, spans the Mississippi River connecting Rock Island, Illinois and Davenport, Iowa. It is located near upper Mississippi mile 483, adjacent to Mississippi River Lock and Dam No. 15. The current structure, the fourth in a succession at this location, includes a swing section to accommodate traffic navigating the locks. The double tracks of rail above the road level is an unusual feature for a bridge.
The original bridge at the site, finished in 1856, was the first railroad bridge across the Mississippi. The bridge represented a threat to the South, which sought to create a southern rail route to the Pacific, and to Saint Louis, whose steamboats faced competition from Chicago's railroads.
The first bridge, constructed in the 1850s and located around 1,500 feet (460 m) upstream of the present, was the first railroad bridge to ever span the Mississippi River and played prominent roles in the ramp up to the American Civil War and construction of the First Transcontinental Railroad.
The bridge connected the Chicago and Rock Island Railroad with the newly created Mississippi and Missouri Railroad proposed by Thomas C. Durant as the first railroad in Iowa, linking Davenport and Council Bluffs. Companies operating steamships on the Mississippi opposed the bridge fearing that it would pose a navigation hazard and that it would alter their monopoly on trade.
Since the bridge crossed an island that was formerly the home of Fort Armstrong, the Department of War had a say in the construction (even though Fort Armstrong had closed in 1845). Future Confederate President Jefferson Davis, who was Secretary of War under President Franklin Pierce initially approved the bridge thinking that the first transcontinental railroad was going to go through the South to Los Angeles, California. However, as resistance to this plan began to surface Davis opposed the bridge fearing that it would result in the transcontinental railroad going through the north. Davis ordered the construction halted but was ignored.
Davis had no luck in getting the courts to agree with him and the bridge was built opening on April 22, 1856.
The bridge had been built in a difficult part of the rapids, and its drawspan was at an angle to the current, making the bridge hard for steamboats to clear. Many felt that the bridge had been intentionally constructed to interfere with steamboat traffic. On May 6, 1856, the steamer Effie Afton collided with the bridge after one of its paddles stopped. The crew were rescued, but the steamer caught fire, damaged the bridge, and sank. Steamboat companies sued to have the bridge dismantled. The M&M and the Rock Island Line hired Abraham Lincoln to defend the bridge. The case worked its way to the Supreme Court and was decided in the bridge's favor in 1862 during the Civil War. In the meantime, the M&M and Rock Island merged to become the Chicago, Rock Island and Pacific Railroad. Durant took his earnings from the M&M merger to form a new company called the Union Pacific Railroad. Lincoln in doing research as private attorney visited M&M facilities and met with various M&M officials in Council Bluffs. When the Pacific Railway Act of 1862 gave Lincoln the power to decide the eastern terminus of the transcontinental he picked a location that was most favorable to his former clients. The case eventually ended in a hung jury, and was dismissed. The US Supreme Court eventually decided a subsequent suit in December 1862, and the bridge remained operational.
The first bridge only lasted until 1866, at which time it was considered inadequate for the ever increasing loads carried by the railroad. It was replaced by a heavier wooden structure that reused the original piers. In turn, this structure was replaced by an iron, twin deck bridge in 1872 that carried both a single rail line and a separate roadway. This bridge was at a new location on the western tip of Arsenal Island and the original bridge and rail line was abandoned. The relocation was driven by the federal government, which still owned the island and wished to redevelop it into an arsenal. The original bridge and rail line severed the property in two and this development constraint was removed by relocating the bridge to an extreme end of the island. The federal government jointly used this bridge for access with the railroad, giving rise to the current name - Government Bridge.
The current Government Bridge is the fourth crossing of the Mississippi in this vicinity, having been built in 1896 on the same location and using the same piers as the 1872 structure. It too is a twin deck structure that carries both rail (top level) and road traffic (bottom level), but it increased the rail lines from one to two to ease what had become a rail traffic bottleneck. It was designed by Ralph Modjeski and built by the Phoenix Bridge Company. Despite being well over a century old, a 2006 stress test revealed the bridge had only used "10 to 12 percent" of its service life. 
All that remains of the first bridge is an elevated approach west of River Drive on the Iowa side, and a reconstructed pier on Arsenal Island.
- Jackson, Donald C. (1988). Great American Bridges and Dams. Wiley. p. 198. ISBN 0-471-14385-5.
- "Bridges: Iowa, Illinois order safety inspections". Quad City Times. Retrieved 2007-12-19.
- Hess, Jeffrey A.; Arborgast, David (February 1985). "Historic American Engineering Record: Rock Island Arsenal/Rock Island Bridge (Government Bridge)" (PDF). National Park Service. Retrieved April 30, 2012.
- Tweet, Roald D. The Quad Cities: An American mosaic. East Hall Press. 1996.
- "Bridging the Mississippi: The Railroads and Steamboats Clash at the Rock Island Bridge" By David A. Pfeiffer - Prologue Magazine - Summer 2004
- A Brief Historical Overview of the Chicago, Rock Island, and Pacific Railroad
- The Quad City Times - The Big Story: Behold the secrets of the Government Bridge
- USACE - The Rock Island Government Bridge
- Bridging the Mississippi: The Railroads and Steamboats Clash at the Rock Island Bridge
- Historic American Engineering Record (HAER) No. IL-20-P, "Rock Island Arsenal, Rock Island Bridge"
- Rock Island Government Bridge at Structurae
- History of the First Railroad Bridge Across the Mississippi by River Action