Clarkson-Knowles Cottage
Why it's listed
Built around 1830 in the heart of Potsdam, this 1 1/2-storey Federal style cottage at 37 Main Street is made of local Potsdam sandstone. Its front wall shows the "slab and binder" technique, in which thick vertical slabs alternate with thin horizontal binders, while the side and back walls use more random stonework. The house keeps its centered entry with transom, flared window lintels, narrow central stairwell, pine plank floors and several original doors. Only about 25 sandstone houses survive in the Potsdam area, and this is the village's sole remaining Federal style sandstone cottage. John C. Clarkson, a proprietor of the town, probably built it as an investment. In 1837 it passed to lawyer Liberty Knowles, a leader of the Presbyterian congregation and a trustee of St. Lawrence Academy, and then to his sons, who held it until 1873. Later additions were removed in 1981 and replaced by a compatible rear wing.
Significance in brief: The form argues the cottage is architecturally significant as a well-preserved, no longer common example of the local "slab and binder" sandstone masonry, and the only surviving Federal style sandstone cottage in the village. It is also significant for its ties to the Clarkson and Knowles families, who were prominent in Potsdam's settlement and its growth as an educational center.
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 95001405, listed December 7, 1995. Summary generated October 2026 (model claude-sonnet-5-5, prompt v1.0-2026-10-29, confidence high).
Key facts
| Address | 37 Main St., Potsdam |
|---|---|
| County | St. Lawrence County |
| Listed | December 7, 1995 |
| Reference number | 95001405 |
| Resource type | Building |
| Period of significance | c.1835-1873 |
| Architect / builder | unknown |
| Architectural style | Early Republic/Federal |
| Criteria |
|
| Areas of significance | Exploration/Settlement, Architecture |
| Level of significance | Local |
| Status (as stated in the nomination) | Used as a single dwelling; the first floor has been returned to its original 1830s layout, the wood shingle roof restored, and a rear wing built in 1981. |
| Acreage | 0.9 |
| Coordinates | 44.66838, -74.98302 (NPS GIS) |
What listing means for this property
National Register listing is honorary for a privately owned home: it does not by itself restrict what an owner may do with their own money, and it does not require public access. Restrictions come from local landmark or historic-district ordinances, which are separate (how they differ).
Owner-occupied houses are not eligible for the 20% federal rehabilitation tax credit, which applies to income-producing buildings, but many states offer credits for homeowners. Listing also opens the door to preservation easements and to buying a plaque. Start with what listing means for homeowners, renovating a listed house and selling one.
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 95001405.
- Nomination form (PDF, National Archives) — catalog entry
- Wikipedia article (used for cross-checking only; text not reproduced here)
- Wikidata Q5127630
- This listing as JSON
Last updated October 2026. Found an error? See the editorial policy for how to report it.