Clear Spring was a lively Unionist community on the National Road during the Civil War, though some local men joined Confederate units while many enlisted in the Federal 1st Potomac Home Brigade Cavalry and Company B, Cole’s Cavalry. In nearby Four Locks on January 31, 1861, residents raised a 113-foot-high Union Pole with a streamer proclaiming “Union Forever.” A Federal detachment occupied Clear Spring and maintained a signal station on nearby Fairview Mountain, and on May 23 the Clear Spring Guard drove off Confederates attempting to capture the boat at McCoy’s Ferry on the Potomac River south of town. In December, Confederate General Thomas J. "Stonewall" Jackson’s troops attacked the nearby Chesapeake and Ohio Canal. After the Confederate retreat to western Virginia following the Battle of Antietam on September 17, 1862, General Robert E. Lee sent General J.E.B. Stuart and more than 1,000 cavalrymen on a raid around the Union army; Stuart crossed at McCoy’s Ferry on October 10 and rode through Clear Spring to Mercersburg and Chambersburg, Pennsylvania, seizing prisoners, horses, and supplies before escaping through Maryland. During the Confederate retreat from Gettysburg in 1863, a large cavalry rearguard action involving more than 1,500 cavalrymen began in Clear Spring on July 10 and continued toward Williamsport. In 1864, Confederate cavalry Generals John McCausland and Bradley Johnson crossed into Maryland at McCoy’s Ferry on July 29, drove a 400-man Union force from Clear Spring, and McCausland rode to Chambersburg and burned it the next day.
