From the late 1700s into the 1800s, the pastoral calm of the Point was interrupted repeatedly—by soldiers manning cannon emplacements, by surveyors laying out the boundaries of the nation's capital, by workers at a ropewalk and the lighthouse, and by Union troops constructing a gun battery to defend the federal city during the Civil War.
During the Revolutionary War, cannon positions were established on Jones Point. These defenses were enlarged during and following the War, but eventually abandoned. However, it would not be the military's last use of Jones Point.
The survey that defined the original ten-mile square of the District of Columbia began here when surveyor Andrew Ellicott and Benjamin Banneker, a free black farmer and self taught mathematician and astronomer, placed the south cornerstone on Jones Point in 1791. Although the cornerstone still stands today—located behind the 19th century lighthouse—the land on this side of the Potomac River was returned to Virginia in 1847.
A growing maritime industry brought a ropewalk to Jones Point, which manufactured ship's rope from 1833 to 1850. By 1856, Jones Point also had a lighthouse that guided ship traffic to the bustling ports of Georgetown and Alexandria. When the Civil War began, these points found themselves on opposing sides. Union forces quickly occupied Confederate Alexandria, and in 1863 completed a gun emplacement above Jones Point cove. Along with Forte Foote in Maryland, Battery Rogers guarded the Potomac River approach to the capital.