Trenton City/Calhoun Street Bridge
Also known as: Calhoun Street Bridge
Why it's listed
Wrought-iron roadway bridge crossing the Delaware River between Trenton, New Jersey, and Morrisville, Pennsylvania, completed by 1885. Its 1,280-foot length is divided into seven Pratt truss spans of nine panels each, with trusses 26 feet deep. The compression members are Phoenix columns, round members made of four rolled semicircular sections riveted together. Samuel Reeves of the Phoenix Iron Works patented the design after Wendel Bollman, an engineer for the Baltimore and Ohio Railroad, worked on a similar hollow column. The superstructure was fabricated by the Phoenix Bridge Company of Phoenixville, Pennsylvania. The abutments and piers are rough stone, with cut-block on the upstream ice-breaker edge. It is significant as one of the few surviving long bridges of this type, probably the longest Phoenix bridge, and it is still open to traffic. It is also the second oldest bridge on the Delaware River, after Roebling's Lackawaxen Aqueduct.
Significance in brief: The bridge is one of the few surviving long bridges built with Phoenix columns, a type of built-up wrought-iron compression member that was widely used from about 1867 to the late 19th century. The nomination states it is probably the longest Phoenix Bridge and that it remains open to traffic. It is also described as the second oldest bridge on the Delaware River, after Roebling's Lackawaxen Aqueduct.
Machine-generated summary. This summary was generated by a language model from the official nomination document and has not been reviewed line by line by an editor. It may contain errors. Check the source document before relying on any detail. Source: nomination document (PDF) · National Archives catalog entry. NRHP reference 75001621, listed November 20, 1975. Summary generated October 2026 (model claude-haiku-5-5, prompt v1.1-2026-10-29, confidence medium).
Key facts
| Address | Spans Delaware River between Morrisville, PA and Trenton, NJ, Morrisville |
|---|---|
| County | Bucks County |
| Listed | November 20, 1975 |
| Reference number | 75001621 |
| Resource type | Structure |
| Period of significance | 1885 |
| Architect / builder | Phoenix Bridge Company, Phoenixville, Pennsylvania (superstructure fabricator); Trenton City Bridge Company with F. C. Larvthortp, consulting engineer (erection) |
| Architectural style | Pratt truss with Phoenix column |
| Areas of significance | Industry, Transportation |
| Level of significance | National |
| Status (as stated in the nomination) | In good condition; the wooden deck has been replaced by a steel lattice and the bridge remains open to traffic. |
| Acreage | 3.3 |
| Coordinates | 40.21985, -74.77784 (NPS GIS) |
What listing means for this property
For a publicly owned building or structure, listing mainly matters when federal funds, permits or licences are involved: projects then go through Section 106 review so effects on the property are considered. Listing also strengthens applications for preservation grants and, for leased income-producing uses, can enable the federal rehabilitation tax credit.
General information, not legal or tax advice. Rules change; confirm with your State Historic Preservation Office or a qualified adviser.
Sources and further reading
- National Park Service, National Register of Historic Places database (snapshot May 2026), reference 75001621.
- Nomination form (PDF, National Archives) — catalog entry
- Wikipedia article (used for cross-checking only; text not reproduced here)
- Wikidata Q5019790
- This listing as JSON
Last updated October 2026. Found an error? See the editorial policy for how to report it.