In May 1861, General P. G. T. Beauregard ordered the development of coastal defenses for South Carolina, including batteries situated on three islands flanking the mouth of Winyah Bay: North Island, South Island, and Cat Island. The Federal capture of Port Royal in November 1861 lent urgency to the construction and improvement of these works, which was done under Robert E. Lee, the newly appointed commander of the Department of South Carolina, Georgia, and East Florida, with Colonel Arthur Middleton Manigault in charge of the district that included Georgetown and Horry counties.