Early in July, after he had taken command of the South Atlantic Blockading Squadron, Rear Adm. John A. Dahlgren ordered the monitors back to Charleston harbor. "Nahant", now under the command of William Kennon Mayo, and her sisters bombarded Confederate works on Morris Island on July 10, supporting and covering the landing of Army troops. For almost two months, the shelling continued until the steadfast defenders were finally compelled to abandon Battery Wagner, their last position on the island, on September 6.