The first two bridges over Quincy Bay were built about one half mile south of this location. That includes an 1868 swing span, and a replacement 1899 bridge that still stands as the Quinsippi Island Bridge. When the Chicago, Burlington, and Quincy replaced the rail crossing at Quincy in 1960, they used a new alignment that ran north of the existing bridges.
This bridge is one of the more modern railroad bridges on the upper Mississippi River. As a result, it was built high above the water. This span is not built this high for navigation reasons, rather, the main channel bridge is just west of here, and trains do not work well with sudden changes in track elevation. The bridge connects the high main channel bridge to some bluffs on the east side of the river.