While aiding others, Barton, for a time, forgot herself. Her “work and words,” she insisted, were solely bound up in “the individual soldier—what he does, sees, feels, or thinks in ... long dread hours of leaden rain and iron hail.” As she gained self-confidence and acclaim, she shed her morbid introspection. Once when she was asked if her work had been interesting, she gave a revealing reply: “When you stand day and night in the presence of hardship and physical suffering, you do not stop to think about the interest. There is no time for that. Ease pain, soothe sorrow, lessen suffering—this is your only thought day and night. Everything, everything else is lost sight of—yourself and the world.”
In April 1863, Barton transferred her base from Washington to Hilton Head Island off the coast of South Carolina. She had been advised that a major siege of Charleston would be attempted and believed she could be most useful there. She also hoped to be closer to her brothers: Stephen lived behind Confederate lines in North Carolina, and David had been sent by the army to Hilton Head in the early days of 1863.
During the eight-month siege of Charleston, she worked on the battlefields of Morris Island and Fort Wagner and helped nurse soldiers dying of malaria and other tropical fevers. Charleston proved to be a less active spot than anticipated, however, and this fact, coupled with a growing rift between Barton and hospital authorities, led her to leave the area in January 1864. She returned to Washington, where she continued to gather supplies as she awaited her next chance for service.
Her chance came in May 1864, when “the terrible slaughter of the Wilderness and Spotsylvania turned all pitying hearts once more to Fredericksburg.” Here she witnessed some of the most frightening scenes she ever encountered. Fifty thousand men were killed or wounded in the Wilderness Campaign. “I saw many things that I did not wish to see and I pray God I may never see again,” she told a friend. Rain turned the red clay soil of Virginia to deep mud, and hundreds of army wagons, crowded full of wounded and suffering men, were stuck in a tremendous traffic jam. “No hub of a wheel was in sight and you saw nothing of any animal below its knees.”