The swing span was last operated in 1976 to permit the passage of barges upriver carrying construction equipment for the Westmorland Street Bridge project.

This project became such a certainty by the mid-1860s that the city of Fredericton actually moved its entire agricultural exhibition grounds (at great expense) from a location near the present-day York Street Railway Station to the current location of the Fredericton Exhibition in order to accommodate this railway project.

Further E&NA surveys, along with significant lobbying from the city of Saint John, saw the "Western Extension" project altered to run from Saint John's west end, northwest to Harvey and then west to McAdam, thereby avoiding Fredericton by approximately 40 kilometres (25 mi).

This line opened in 1869 and forced the construction of the Fredericton Branch Railway to serve the capital city.

As part of this project, Gibson again proposed to build a railway bridge over the Saint John River and in 1885, he incorporated the Fredericton and St. Mary's Railway Bridge Co. Construction began in 1887 with the laying of the first foundation stone, assisted by Prime Minister of Canada, Sir John A. Macdonald and his wife Lady Macdonald.

CNR replaced it with the current structure which was officially opened by federal Minister of Transport, the Honourable C. D. Howe, on June 1, 1938.

The ceremony was attended by hundreds of local citizens to celebrate the restoration of rail service across the river which had been severed 17 months earlier.

Rail traffic in Fredericton declined during the post-war era as new highways were opened and shippers converted to trucks.