Edwards Ferry was a strategically important Potomac River crossing from June 1861 through the end of the Civil War. Union troops first camped there in June 1861, and in December 1861 Professor Thaddeus Lowe, U.S. Chief of Aeronauts, established a base there for frequent balloon ascents to observe Confederate movements across the river near Leesburg; despite Confederate camouflage and concealment, the reconnaissance proved fruitful and continued until March 1862, and Gen. Charles P. Stone made at least one ascent himself. Gen. Joseph Hooker’s seventy-five thousand-man, seven-corps Army of the Potomac crossed the river there on June 25-27, 1863, on the way to Gettysburg, using two one thousand four hundred-foot-long pontoon bridges despite heavy rains that made the single road to and from the bridges extremely muddy. On the afternoon of June 28, Confederate Gen. J.E.B. Stuart’s cavalrymen, having crossed into Maryland just south of there at Violettes Lock, burned fifteen barges loaded with government stores in the Chesapeake and Ohio Canal nearby and captured the mules and men working them. Confederate surprise attacks continued throughout the war: in August 1863, Col. Elijah V. White’s 35th Battalion Virginia Cavalry captured sixteen Union soldiers and thirty-five horses and mules; during Gen. Jubal A. Early’s retreat after he threatened Washington in July 1864, his cavalry destroyed the Union camp, the canal lock, and several canal boats; and in February 1865 Confederates attacked again across the frozen river, bringing back fourteen horses and equipment.