South Carolina’s Cape Island has long been known for its loggerhead turtle-nesting beaches and its place in the Class I wilderness area at Cape Romain National Wildlife Refuge. Now, the island also is known as a site to commemorate one of the most courageous acts in American history.

The refuge recently learned from the National Oceanic and Atmospheric Administration (NOAA) that remains of the USS Planter likely have been found on a shoal about one-third of a mile off today’s Cape Island. The remains are buried in 15 feet of compacted sand 12 feet below the Atlantic Ocean’s surface at what was the island’s southern tip in 1876, when the side-wheel steamer was abandoned.

The Planter launched in 1860 as a commercial vessel. A year later, with the outbreak of the Civil War, it became the armed Confederate States Ship (CSS) Planter. But in the pre-dawn hours of May 13, 1862, Robert Smalls, a 23-year-old enslaved African American crewman on the steamer, commandeered the 147-foot vessel in Charleston harbor, snuck it past Confederate forces and turned it over to the Union Navy. In the process, Smalls carried himself and 17 other black slaves aboard the Planter to freedom.

"When I learned of Smalls’ bravery and subsequent accomplishments, I was awed and felt a rush of exhilaration," says Raye Nilius, project leader of the South Carolina Lowcountry Refuges Complex, which includes Cape Romain Refuge. "His story truly resonates with me, as I believe it resonates with many Americans whose immigrant ancestors came to this country to escape persecution and oppression."

During the remainder of the Civil War, Smalls became captain of what was by then the USS Planter. After the war, Smalls went on to serve, as a Republican, in the South Carolina Legislature and, for five nonconsecutive terms, in the U.S. House of Representatives. He died in 1915 in the city of his birth, Beaufort, SC.

The Planter returned to commercial service after the Civil War. While attempting to rescue a schooner that had run aground in March 1876, the Planter itself sprang a leak, was beached at Cape Island and, after being battered by storms, had to be abandoned.

NOAA and maritime research partners first detected the remains in 2010 by using historical and cartographic data and remote-sensing magnetometer and sonar technology. NOAA did not announce its conclusion that "it has determined the probable location of the remains" of the Planter until this May.

"We consider it an honor that the ship’s final resting place is on Cape Romain and will long revere these heroes while we enjoy life in a nation where freedom is paramount," says Nilius.

Cape Romain Refuge is home to several other important cultural resources: Mill Island, where a wind-powered sawmill owned by the family of Declaration of Independence signer Thomas Lynch produced lumber in the late 1700s; Bulls Island, which has a rich Native American, pirating, Civil War and early conservation history; and two lighthouses on the National Register of Historic Places.

The discovery of the Planter stands apart, though.

"The bravery shown by Mr. Smalls and the success of the mission gave the enslaved hope during the Civil War and boosted resolve to win a war for the freedom of all Americans," says Cape Romain Refuge manager Sarah Dawsey. "I believe it is quite relevant with President Obama being the first African American president of the United States. If the Union lost the Civil War, then I dare say we would most likely not have an African American president."