Southwest No. 3 Boundary Marker of the Original District of Columbia
Also known as: SW3,Jurisdiction Stone
Why it's listed
Southwest No. 3 is a sandstone boundary marker in the parking lot of a church on King Street in Alexandria, Virginia. It is one of the stones set to mark the edge of the original District of Columbia. The stone now measures about 12 by 11 by 19 inches, and its top and edges are chipped, so part of the inscription is gone. The surviving text includes "M 302p," meaning two miles and 302 poles. A wrought iron fence, painted silver and placed in June 1917, surrounds it. The marker is notable for its spacing. It was the first Virginia stone not set at an equal mile interval, because the end of the third mile fell in a ravine. Surveyors placed it on higher ground, slightly less than three miles from the South Cornerstone at Jones Point. Its listing rests on its link to the creation and layout of the federal city, with a period of significance from 1791 to 1917.
Significance in brief: The stone marked the third mile on the southwest side of the District, measured from the South Cornerstone at Jones Point. It was the first marker in Virginia placed at other than an equal-mile interval, because the end of the mile fell in a ravine. It is tied to the development of the federal city.
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 91000008, listed February 1, 1991. Summary generated October 2026 (model claude-sonnet-5-5, prompt v1.0-2026-10-29, confidence medium).
Key facts
| Address | 2952 King St., Alexandria (Independent City) |
|---|---|
| County | Alexandria |
| Listed | February 1, 1991 |
| Reference number | 91000008 |
| Resource type | Object |
| Period of significance | 1791-1917 |
| Architect / builder | Unknown |
| Criteria |
|
| Areas of significance | Community Planning and Development, Politics/Government |
| Level of significance | National |
| Status (as stated in the nomination) | The top and edges are chipped and part of the original inscription is missing. The stone sits among painted parking places in a church parking lot, inside a silver-painted iron fence placed in 1917. |
| Acreage | 0.9 |
| Coordinates | 38.82066, -77.07938 (NPS GIS) |
What listing means for this property
National Register listing is honorary: it recognises significance and does not restrict what a private owner may do without federal money or permits. It unlocks the 20% federal rehabilitation tax credit for income-producing buildings, state credits in many states, and Section 106 review when federal agencies are involved. See what listing means in practice.
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 91000008.
- 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.