Harlan House
Also known as: Star Gazers House; Star Gazer Farm
Why it's listed
Set in the rolling hills near the Brandywine Creek, this farmhouse dates to about 1724 and was built as a fieldstone two-bay core, with a stone addition of about 1758 and a 19th-century frame wing. The addition retains its original double fireplace, including a walk-in cooking hearth with a flagstone floor, a crane and an oak lintel, which the document describes as the most notable feature of the house. Its masonry construction is considered a rare and accomplished example of mid-18th-century vernacular building among the homes of Quaker and Scotch-Irish settlers in southern Chester County. The Harlan family lived here until 1956. Its importance also lies in the 1764 to 1768 stay of the astronomers Charles Mason and Jeremiah Dixon, who set up a temporary observatory here. From a point north of the house they measured an arc of meridian used to survey the boundary between Pennsylvania and Maryland. The marker they left, the Star Gazers' Stone, is still in a field 700 feet north of the house.
Significance in brief: The house is argued to be an excellent example of early 18th-century Colonial vernacular masonry architecture, with its walk-in cooking fireplace a notable feature. The site is significant because Mason and Dixon used a temporary observatory near the house in 1764-68 to survey the Pennsylvania-Maryland boundary, later known as the Mason-Dixon Line, which contributed to surveying methods and knowledge of the earth's size and shape.
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 85001004, listed May 9, 1985. Summary generated October 2026 (model claude-haiku-5-5, prompt v1.1-2026-10-29, confidence high).
Key facts
| Address | PA 162 and Star Gazer Rd., Embreeville |
|---|---|
| County | Chester County |
| Listed | May 9, 1985 |
| Reference number | 85001004 |
| Resource type | Building |
| Period of significance | 1724-1768 |
| Architectural style | Colonial vernacular |
| Criteria |
|
| Areas of significance | Engineering, Exploration/Settlement, Science, Architecture |
| Level of significance | State |
| Status (as stated in the nomination) | The house was the Harlan family residence until 1956; the document does not state its current condition or use. |
| Acreage | 9 |
| Coordinates | 39.93827, -75.73193 (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 85001004.
- Nomination form (PDF, National Archives) — catalog entry
- Wikipedia article (used for cross-checking only; text not reproduced here)
- Wikidata Q7600726
- This listing as JSON
Last updated October 2026. Found an error? See the editorial policy for how to report it.