Fort Dupont had six sides, each 100 feet long, protected by a deep moat and trees felled side-by-side with branches pointing outward. It was named for Flag Officer Samuel F. du Pont, who commanded the naval victory at Port Royal, South Carolina, in November 1861.

Although its garrison and guns never saw battle, Fort Dupont served as a lifeline of freedom. Runaway slaves found safety here before moving on to join the growing community of "contrabands" in Washington. The barracks and guns are gone, but the fort's earthworks can still be traced near the picnic area on Alabama Avenue.

In the 1930s, the National Capital Planning Commission acquired the old fort and surrounding land for recreation. An 18-hole golf course was constructed. As the city grew, golf gave way in 1970 to the sports complex along Ely Place that now includes tennis and basketball courts, athletic fields, and a softball diamond. An indoor ice rink offers skating all winter. Where once the Civil War fort looked out over farmlands, city dwellers now grow vegetables in community garden plots.