The oldest set of federally placed monuments in the United States are strewn along busy streets, hidden in dense forests, lying unassumingly in residential front yards and church parking lots. Many are fortified by small iron fences, and one resides in the sea wall of a Potomac River lighthouse. Lining the current and former boundaries of Washington, D.C., these are the boundary stones of our nation’s capital.

The story of the boundary stones begins with the Residence Act of 1790, which approved of the creation of a new national capital along the Potomac River in the shape of a diamond 10 miles on each side, for a 100 square mile area. The new capital would be carved out of land from Maryland and Virginia. President George Washington, himself an accomplished surveyor, designated Jones Point to be the southern point of the diamond, with the rest of the territory to be surveyed and mapped from there. Beginning in 1791, a team led by Andrew Ellicott, and including famed astronomer and intellectual Benjamin Banneker, set out from Jones Point to perform an initial survey of the new territory. Although Banneker was forced to drop out of the project due to illness, Ellicott and his team were able to complete the full survey on the Virginia and Maryland sides of the Potomac River in 1792. At each mile of the survey, a stone was placed to mark the boundary of the “Territory of Columbia.” In 1846, Virginia’s donated land portion to what had then become the District of Columbia was returned to Virginia, thereby nullifying the original purpose of many of the stones on the diamond’s northwestern and southwestern sides.

The boundary stones were intended to define the territory’s borders and solidify the permanence of the new national capital. But over the years, weathering, urban development, and other factors have taken a toll on the stones themselves. In 1906, Fred E. Woodward visited each boundary stone, took photographs, and documented their conditions. Among his documentations is his Chart showing the original boundary milestones of the District of Columbia, which shows the locations of each boundary stone while noting that several stones were damaged or missing (appearing only as “stumps”).

In a letter to the Columbia Historical Society (today the Historical Society of Washington, D.C.), Woodward called for these stones to be preserved. He wrote:

Important as these ancient boundary stones are to the historian or antiquary, they are singularly unprotected and should at once be safeguarded against further injury or damage other than the necessary exposure to the elements. Such protection might be afforded by a small enclosure about five feet square and five feet high, suitably made of wrought iron of approved national design, to be placed around each stone. In some such manner, may these earlier monuments of the history of the District of Columbia be preserved for those who come after us.

In the years following Woodward’s report, a number of preservation efforts were undertaken to save the stones, including the construction of protective fencing that Woodward had proposed. A boundary stone protected by fencing is shown in the below photograph by Harris & Ewing from 1922.

Today, 36 of the original 40 boundary stones still exist in various physical conditions. Some stones legibly maintain their original inscriptions marking the “Jurisdiction of the United States,” while others have been severely eroded or sunk into the ground so as to now resemble ordinary, naturally-occurring stones. The inclusion of all of the boundary stones into the National Register of Historic Places in the 1990s and various rehabilitation efforts by local and federal government agencies in recent years point to renewed interest in preserving the stones (if perhaps not restoring them to their full, 1790s glory).

In whatever physical state, the boundary stones have largely survived for over 200 years and today remain a series of modest monuments to Washington, D.C.’s past and present.