Cornerstone is a civil rights mural that anchors the corner of the Rockville Town Square near Washington DC. This work faces North Washington Street, a centuries-old roadway dense with Native American, Colonial, Revolutionary, and Civil War history. Three banners with historical text include the "X" marks of twenty illiterate freedmen on a pledge to pay for Rockville's first black school in 1867. The artwork highlights a significant cluster of 18th, 19th and 20th century African American heritage sites located around it, now largely obscured by development.