Mercersburg Historic District (Boundary Increase)
Also known as: See Also:Mercersburg Historic District
Why it's listed
Along South Main Street, where the road bends east at Linden Avenue, twelve properties form a boundary increase to the Mercersburg Historic District. The most prominent is Prospect, a two-and-one-half-story brick Colonial Revival mansion built in 1910 for Harry W. Byron, son of the founder of the Byron Tannery, which was the town's principal industry in the late 19th and early 20th centuries. Its slate gambrel roof, pedimented portico and marble and mahogany interiors set it apart in the area. Rosemont, a nearby Colonial Revival house from about 1910, stands on a triangular lot. Across the street, a row of log, brick and frame houses dating from the late 18th through early 20th centuries recalls the period when the site was a brick yard beside a foundry at the edge of town. The houses are regarded as consistent in age, materials and integrity with the existing district.
Significance in brief: The area is significant for its architecture, showing vernacular buildings from the 18th and 19th centuries alongside Colonial Revival houses from about 1910. The two large Colonial Revival mansions, Prospect and Rosemont, mark the town entrance and reflect the conversion of a former brick yard site to a landscaped residential estate tied to the Byron tannery. The area also connects to the town's industrial and commercial history.
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 89000358, listed May 17, 1989. Summary generated October 2026 (model claude-haiku-5-5, prompt v1.1-2026-10-29, confidence medium).
Key facts
| Address | S. Main St., between Linden Ave. and PA 75, Mercersburg |
|---|---|
| County | Franklin County |
| Listed | May 17, 1989 |
| Reference number | 89000358 |
| Resource type | District |
| Period of significance | 1780-1920 |
| Architectural style | Colonial Revival; Cumberland Valley Vernacular |
| Criteria |
|
| Areas of significance | Architecture |
| Level of significance | Local |
| Status (as stated in the nomination) | Prospect was historically rehabilitated in 1987 and has operated as an inn intermittently since the 1950s; 213 S. Main Street has been an antique shop in recent years. |
| Acreage | 10 |
| Coordinates | 39.82317, -77.90221 (NPS GIS) |
What listing means for this property
This is a historic district. Buildings within its boundary are either contributing (they add to the district's significance) or non-contributing. Owners of contributing income-producing buildings can claim the 20% federal rehabilitation tax credit; homeowners should look at state credits. National Register districts impose no design review by themselves; a local historic district ordinance, if one exists, does (the difference explained).
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 89000358.
- Nomination form (PDF, National Archives) — catalog entry
- This listing as JSON
Last updated October 2026. Found an error? See the editorial policy for how to report it.