Benjamin Banneker was one of the most famous black men in colonial America. He was a farmer, a mathematician, an inventor, an astronomer, a writer, a surveyor, a scientist, and a humanitarian.
When he surveyed the city of Washington with Major Pierre Charles L'Enfant, Banneker became one of the first black civil servants of the new nation. Along with a team, Banneker identified the boundaries of the capitol city. They installed intermittent stone markers along the perimeter of the District.
The SW-9 Intermediate Boundary Stone of the District of Columbia, located in Arlington, Virginia, is still in place. The east side of the stone bears the engraving, "Virginia" and the north side, "1791,” the year Banneker helped survey the city.
This Boundary was was designated a National Historic Landmark in 1976.