Before this bridge was built, the main line of the the New York, New Haven & Hartford Railroad went right through South Norwalk's busiest intersection at grade level. In order to safely run trains through the area, the railroad eliminated the grade crossing when it rebuilt the line from two tracks to its present width of four tracks. Although the heavy ironwork and massive stone abutments of the South Norwalk Railroad Bridge create a looming presence over South Norwalk's downtown, the effect must have seemed a small price to pay compared with the constant danger of injury from passing trains running at street level. The bridge remains practically unchanged from its original appearance, other than the overhead electrification wires first installed in 1907.
The South Norwalk Railroad Bridge was designed by the New Haven Railroad's own engineers, so it bears little resemblance to other Berlin Iron Bridge Company products. It is a typical railroad design using a standard truss pattern (the Pratt truss). The New Haven Railroad contracted with several different bridge fabricators for all the new bridges that were needed because of the widening to four tracks and the elimination of grade crossing. This bridge, the drawbridge to the east across the Norwalk River, and several other smaller bridges were supplied by the Berlin Iron Bridge Company.
In addition to its significance as a product of the Berlin Iron Bridge Company, this bridge is notable as one of the few remaining large 19th-century railroad trusses in Connecticut. Its pinned connections, heavy structural members, and use of three parallel trusses rather than two all reflect the exceptionally heavy loads that the bridge was designed for.