During the Civil War, although she opposed secession, Ellen enlisted in the cause of the Confederacy. Her son, Richard Call Long, Sr., served in the 2nd Florida Cavalry and she opened The Grove to Confederate officers and to wounded veterans. She was one of the members of the Ladies Soldier's Friend Sewing Society, a group of prominent society women in Tallahassee who volunteered their services to provide Confederate soldiers with clothing articles during the war. Ellen opened The Grove for a number of social events during the Civil War, including the Tallahassee May Day festivities held on the grounds on May 1, 1865, less than a week after the city received the news of General Robert E. Lee's surrender. The Second Florida cavalry band provided music for the event, which was likely the last performance of the group as the Union army, under General Edward McCook, arrived in the city on May 10, 1865.