Fort Pemberton was one of the larger confederate forts was constructed in the defense of Charleston, South Carolina during the American Civil War. When Charleston was overwhelmed by Union forces in 1861, it became evident that control of the western regions of James Island and the Stono River was to be an important element in the defense of the city. Confederate military authorities of the time believed that Union occupation of James Island would leave Charleston subject to attack from the southeast. From this position the city would assuredly fall to the Union. Although there were many gun batteries in place along the south and east side of James Island, Fort Pemberton was the only fortress in defense of this region.