The Battle for Sullivan’s Island

A satellite image shows Sullivan’s Island, South Carolina, with a sandy shoreline along the Atlantic Ocean to the south, development across the interior, and green marsh and tidal inlets along its north side.

Signs of the marshy, sandy terrain that helped colonists repel invading British forces in a pivotal battle in June 1776 remain visible on Sullivan’s Island in this image acquired on June 3, 2026, by the OLI (Operational Land Imager) on Landsat 8.

NASA Earth Observatory/Michala Garrison

As Thomas Jefferson and the Committee of Five presented their first draft of the Declaration of Independence in Philadelphia on June 28, 1776, several British warships and thousands of troops were massing around Sullivan’s Island in South Carolina.

The pitched battle for the sandy barrier island at the mouth of Charleston Harbor that played out over the course of that June day was one of the most significant in the early stages of the Revolutionary War. By nightfall, largely untested colonial troops had decisively defeated the British, an outcome that helped save Charleston from occupation and buoyed American spirits at a critical stage of the war.

The Landsat 8 satellite captured this image of the island on June 3, 2026. Two hundred fifty years earlier, the sandy beaches, salt marshes, and general shape of the island would have looked similar, though with less evidence of roads or other signs of human development.

There certainly would have been some signs of human activity on the island, however. Quite noticeable would have been Fort Sullivan, a large square structure built from palmetto logs on the southern tip of the island, near the entrance to the harbor. Though one side of the fort, assembled largely by enslaved people, was still unfinished at the time of the battle, the other sides had 16-foot-wide walls packed with sand and containing planked gun platforms that mounted 31 cannons.

Historical maps show at least one road extending from the southern to northern tip of Sullivan’s Island, where hundreds of colonial soldiers were also encamped to protect Breach Inlet from a force of roughly 3,000 British troops massing on nearby Long Island (now Isle of Palms). When the battle began, historians estimate that there were roughly 800 colonial troops, including dozens of Catawba warriors, defending the northeastern part of Sullivan’s Island, embedded within earthen defenses and manning two artillery pieces.

A wider version of the satellite image shows Sullivan’s Island, centered, in relation to Charleston, which lies to the northwest.

June 3, 2026

When the British attack came on the morning of June 28, 1776, both military tactics and geography played critical roles in determining the outcome. Having been told the water at the inlet was less than 18 inches (46 centimeters) deep at low tide, the British commander had planned to have his forces walk across Breach Inlet on foot. But he was forced to pivot to a more dangerous amphibious assault using flatboats when he realized the shallowest part of the break was at least 7 feet (2 meters) deep at low tide. Traveling by flatboat limited the number of British troops who could cross the channel at once, making it easier for colonial defenders to repel them during fierce skirmishing throughout the day.

On the other side of the island, British warships had dropped anchor near Fort Sullivan and begun launching thousands of cannonballs and exploding shells at the fort. However, the natural durability and pliability of the palmetto wood absorbed incoming fire “like sponges,” Colonel William Moultrie, the fort’s commanding officer, later noted in his memoirs.

Most incoming shells that fell within the fort’s walls were neutralized. There was a marshy “morass” in the center of the fort, Moultrie wrote, that “swallowed” up incoming fire “instantly.” Shells that made it over the walls and “fell in the sand, in and about the fort, were immediately buried, so that few of them burst amongst us,” he wrote.

With their limited powder, the colonists focused their fire on the ship carrying the British commander, Sir Peter Parker, severely damaging it and ultimately killing 40 people on board. By the evening, exhausted from the 10-hour battle and making little progress, the British forces retreated.

“We never had such a drubbing in our lives,” one Royal Navy sailor wrote. After the battle, the fort became known as Fort Moultrie, and the palmetto tree began appearing on the state seal in what would prove to be an enduring symbol of colonial pride and resistance. Six days after the battle, the Declaration of Independence was adopted in Philadelphia.

NASA Earth Observatory images by Michala Garrison, using Landsat data from the U.S. Geological Survey. Story by Adam Voiland.