Jones Point Light, Where DC Began

The lighthouse here at the tip of Jones Point lit its first beam on May third, eighteen fifty-six, built to warn river traffic away from the sandbars where the Potomac narrows near Alexandria. It is one of the last riverine lighthouses still standing in the Chesapeake Bay area, now owned by the National Park Service.

But the lighthouse is almost a footnote to what lies next to it: the south cornerstone of the District of Columbia, originally set in seventeen ninety-one as part of the survey that carved the federal district out of Maryland and Virginia. Surveyors began here at the Potomac's edge and worked outward in all directions. Virginia's portion of the District, including Alexandria itself, was returned to the Commonwealth, with the transfer completed in eighteen forty-seven. The stone marks the literal starting point of that ten-mile square, the origin of Washington's boundary.