District of Columbia Southern Cornerstone and Jones Point

Historical Significance

The stone marking the southern corner of the District of Columbia marks the spot surveyed in 1791 by Benjamin Banneker, a Free Black mathematician and astronomer born in Maryland. Banneker made his calculations from the survey base camp at Jones Point in the winter of 1791, and the south cornerstone was laid in April.

Since this portion of the District of Columbia retroceded to Virginia in 1847, the cornerstone now marks a point on the Maryland-Virginia line. Visible only at low tide, the cornerstone is in a recess of a retaining wall, east of the lighthouse in Jones Point Park. A portion of the inscription, "The Beginning of the Territory of Columbia," is barely legible in the severely eroded stone.

The layout of the District itself owes much to Banneker's expertise. When architect Pierre L'Enfant was dismissed from the project in 1792, he took the plans for the capital city with him. Banneker, one of the surveyors working with L'Enfant, recreated them in two days, including a complete layout of the streets, parks and major buildings.

The grandson of an enslaved African and a white indentured servant, Banneker was best known in his lifetime for the six annual Farmer's Almanacs he published from 1792-1797. A precocious, largely self-taught scientist, Banneker sent a copy of his first almanac to Secretary of State Thomas Jefferson. In an enclosed letter, he questioned the slaveholder's reputation as a "friend to liberty" and urged Jefferson to speak out against the "absurd and false ideas" of racial superiority. Jefferson responded with praise for Banneker's accomplishments. 

Physical Description

The south cornerstone is in a recess of a retaining wall in Jones Point Park, just east of the historic lighthouse. The stone can only be seen at low tide as the sea level has risen over the last 200 years, covering the tip of Jones Point.

Geographical and Contact Information

Jones Point Park
McLean, Virginia
Phone: 703-289-2535
Fax: 703-289-2598