Benjamin Banneker's SW 9 Intermediate Boundary Stone, also known as Intermediate Stone of the District of Columbia, is a surveyors' boundary marker stone. It is a one foot square sandstone block, extending about 18 inches above ground and probably about 2 feet below ground. It is one of 40 original boundary stones of the District of Columbia. It was named and was declared a National Historic Landmark in 1976 at the instigation of the Afro-American Bicentennial Corporation.
Landmarks
Links: en.wikipedia.org
By: forthefallendrms
http://www.boundarystones.org/view.php?stone=SW9
http://www.boundarystones.org/articles/rchs_1897.pdf