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The Boundary Markers of the Original District of Columbia mark the four lines which form the boundaries between Maryland and Virginia, and the 100 square miles of federal territory that became Washington, D.C. The markers were placed by a survey team led by Major Andrew Ellicott between 1791 and 1792. Thirty-six of the original marker stones are still extant and are the oldest federally-placed monuments in the country. This stone, known as the West Cornerstone and the West Jurisdiction Stone, marks the westernmost point of the diamond-shaped boundary.


  • West Cornerstone in Andrew Ellicott Park. Image by Mark Zimmermann
  • Portrait of Andrew Ellicott

On July 16, 1790 (amended March 3, 1791), the Residence Act granted President George Washington authorization to choose the site for a national capital. He was to choose a 100-square-mile plot located on the Potomac River, between the cities of Alexandria, Virginia and Williamsport, Maryland. Washington selected the southernmost location, as it encompassed what is now Old Town Alexandria and a busy port.

The territory chosen, Secretary of State Thomas Jefferson instructed Major Andrew Ellicott, a prominent surveyor, to begin demarcating the 10-mile square of the city limits. He began his work on February 11, 1791. Ellicott hired the Maryland astronomer and surveyor, Benjamin Banneker, to provide the astronomical observations and calculations needed to fix the south corner. Supposedly, "Banneker fixed the position of the first stone by lying on his back to find the exact starting point for the survey ... and plotting six stars as they crossed his spot at a particular time of night."1

The initial survey was completed in April, an event commemorated by the Masonic Lodge in Alexandria on April 15th. The Lodge placed a small, ceremonial stone at Jones Point at the south corner, although it was later replaced with a larger stone bearing the inscription, "The beginning of the Territory of Columbia."

The marker stones are made of soft Aquia Creek sandstone, weigh approximately half a ton (with the exception of the cornerstones), and are separated by one-mile. Those placed more than a mile apart include an additional marking, indicating the extra distance. On each stone, facing D.C. territory is the mile number and inscription "Jurisdiction of the United States." The opposite side features the name of the state the stone borders. The other faces state the magnetic variance of their location and the year the stone was placed.

Thirty-six of the marker stones are still at or near their original location. The West Cornerstone is located along the Virginia/Maryland line in what is now the quarter-acre Andrew Ellicott Park. Many of the stones are surrounded by a fence erected by the Daughters of the American Revolution in 1915. DAR is an organization for women descended from individuals involved in the American Revolution, which has engaged in preservation efforts throughout the Washington, D.C. area, including a 2014 project to clean and restore the markers. Owing to its historical significance, this particular marker was among those added to the National Register of Historic Places on February 1, 1991.

In 2011, the District of Columbia Geographic Information System program used Global Positioning and contemporary survey technology to validate the efforts of Ellicott's team. It found that the historical surveying effort had been conducted with a high level of accuracy. Construction projects and weathering has displaced or destroyed some of the stones, and preservation efforts are ongoing.

1. "Boundary Stones of the District of Columbia." Boundarystones.org. Accessed October 1, 2016. www.boundarystones.org/. "Boundary Markers of the Original District of Columbia." Wikipedia, the Free Encyclopedia. Accessed October 1, 2016. https://en.wikipedia.org/wiki/Boundary_Markers_of_the_Original_District_of_Columbia.