The building of Fort Frederica on St. Simons Island (near the mouth of the Altamaha River) in 1736 marked the beginning of General Oglethorpe's defensive plan for Georgia.

His thinking was influenced heavily by Georgia's maritime geography, which was primarily an uninterrupted series of coastal barrier islands that formed a natural water route, known as the inland passage, offering protection from unpredictable weather and the harsh conditions of the open sea.

A palisade triangular water battery, which was designed to attack incoming ships at the waterline, was located at the base of the hill; it was connected to the main fort by a covered passage.

Separated from the main Spanish invasion fleet, about 15 ships were located at Cumberland Island and were sheltered off the coast near the fort in St. Andrew Sound in June 1742.

In July, when the Spanish forces retreated after the Battle of Bloody Marsh, they camped at the abandoned fort on their return trip to Florida and burned it down.