Here he was attacked by General Lincoln in a spirited but unsuccessful affair, in which the latter was compelled to retreat.
The attack of Lincoln was followed by one of Moultrie, in galleys.

The situation of the British became unpleasant, and they did not wait a repetition of these assaults, but retreated along the chain of islands on the coast, until they reached Beaufort and Savannah.

Both of these places they maintained; the latter with their main army, the former with a strong body of troops, apart from their sick, wounded and convalescent.

Here they were watched by General Lincoln, in a camp of observation at Sheldon, until the appearance of a French fleet on the coast led to renewed activity, and hopes, on the part of the Americans, which were destined to bitter disappointment.
Marion was certainly with his regiment at Sheldon, and when it became probable that there was some prospect of battle, we find him at Fort Moultrie, when Prevost was in possession of the contiguous islands.

But a junction of the French and American forces, necessarily compelling the concentration of the whole of the southern invading army at Savannah, lessened the necessity of his remaining at a post which stood in no manner of danger.
Early in September, 1779, the French admiral, Count D'Estaign, with a fleet of twenty sail, appeared upon the coast.