At 409 feet above sea level, this site is the highest natural point in Washington, D.C. In 1861, the Union army built one of its largest and most heavily armed Civil War fortifications here, originally naming it Fort Pennsylvania and later renaming it for Major General Jesse L. Reno. With commanding views over the surrounding countryside, Fort Reno formed the center of the Union's northern defenses of Washington, D.C., overseeing three major roads that met at Tenleytown: River Road, Rockville Road, and Brookville Road. Along with Battery Reno, the fort covered more than 70 acres with barracks, camps, and a parade ground. During the July 1864 Confederate raid on Washington, D.C., its signal tower first spotted the advancing troops, and its 100-pounder Parrott rifle fired 3.5 miles north, killing Confederate soldiers near the present-day Walter Reed National Military Medical Center. After the war, the army abandoned the fort, and by the late 1800s most of its fortifications had disappeared as reservoirs were created and later residential development spread in the north. To the south and west, African Americans, including some who had helped build the fort and found refuge under its protection during the war, joined working-class white residents to form Reno City, a distinct but segregated neighborhood that was later demolished for Fort Reno Park. In 2007, surveyors established the highest natural ground of the District here, and after a dedication ceremony in April 2008, the highpoint officially became known as Point Reno.