Fort McAllister was a battery erected on the southern banks of the Great Oghechee River in Georgia. On July 7, 1861 Company A of the 1st Georgia Infantry ("DeKalb Rifles") was detached and ordered to build the fort with available materials. Under the command of Lt. Alfred Hartridge, a citizen of Savannah and graduate of the Georgia Military Institute in Marietta the troops constructed the fort to the specifications of Capt. John McCrady [CS], who is generally credited with building the fort.

Captain Robert Martin, commanding the 10-inch mortar, was part of the armament of Ft. McAllister during nine Federal attacks on the works. The mortar moved to the earthworks two miles from the town of Hardwick had seen service during the April, 1861 bombardment of Fort Sumter, Charleston, South Carolina,also under Martin's command.