Archaeologists complete survey of Charleston Harbor Civil War Naval Battlefield

Thanks to a team of archaeologists at the University of South Carolina, the Charleston Harbor naval battlefield has been mapped for the first time, providing historical and archaeological detail on the drawn-out struggle that spanned 1861-1865. The survey shows where military actions took place, where underwater obstructions were created to thwart enemy forces and the spots where Union ironclads and Confederate blockade runners sunk.

The National Park Service, which funded the project through an American Battlefield Protection grant with matching funds from USC, will use the survey to preserve the battlefield. Information gathered about the wrecks and obstructions also will be valuable to harbor managers, the U.S. Army Corps of Engineers and to USC archaeologists to ensure that underwater relics aren't damaged. Their work will also be considered in decisions involving beach renourishment and the deepening of the harbor.

"The archives of South Carolina's maritime history are under water. For years we have had these great resources that we should hold in as much respect as historical documents," said James Spirek, a USC underwater archaeologist. "They are the physical representations of the state's maritime legacies."

Spirek directed the project that began in 2008 and wrapped up this spring. He applied the same approach that was used to understand the historic landscape of Gettysburg to understand the Civil War naval operations at Charleston Harbor.

"The scheme, called KOCOA, is a modern concept based on ages-old military tenets that gets archaeologists and historians to think about how the participants saw the battlefield," Spirek said. "Today, all we see is the aftermath. But how did the battle come to be? And why are things where they are in Charleston Harbor?"

To answer those questions, Spirek had to define the boundaries of the harbor battlefield from the perspective of Union and Confederate forces. He conducted research on Confederate and Union ships and naval actions using official records of the armed forces, the National Archives, Library of Congress and USC's South Caroliniana Library and Digital Collections.

His archaeological work centered on locating the various shipwrecks and obstructions. Two key findings were locating the famous First Stone Fleet, a series of New England whaling and merchant vessels filled with stone and intentionally sunk by Union forces to prevent Confederate blockade runners from entering the harbor, and getting exact locations for the blockade runners, most of which sank in Maffitt's Channel along Sullivan's Island.

Building a boundary

Spirek said Union forces, wanting to keep Confederate supplies from entering and leaving the harbor, created a blockade of naval ships placed in arc fashion that stretched from Dewee's Inlet by the north end of Isle of Palms, then called Long Island, down to Stono Inlet, south of Folly Beach, which was considered the back door to Charleston by traveling up the Stono River.

Between the two inlets and within the arc were five channels that led into the harbor. From north to south were Maffitt's Channel, North Channel, Swash Channel, the Main Ship Channel and Lawford Channel.

The Confederate perspective of the battlefield looked out from Charleston, Spirek said.

Besides the city being fortified there were key points within the harbor itself. Closest to the city was Castle Pinckney and a sand island that was turned into Fort Ripley. In the mouth of the harbor were Fort Sumter and Fort Moultrie on Sullivan's Island and further out was Battery Marshall to the north on Isle of Palms and Battery Wagner on Morris Island to the south, which today is underwater.

Securing the inner harbor was critical to the Confederacy, Spirek said.

"They set up a variety of obstructions including framed torpedoes so that Union ships coming in would hit them and blow up. Chains and rock weights held the torpedoes at an incline and slightly below the water to cause the torpedoes to strike the bottom of a vessel. They essentially created a mine field for Union forces," said Spirek, an archaeologist in the College of Arts and Sciences' S.C. Institute for Archaeology and Anthropology (SCIAA) since 1996.

To help people visualize the Charleston Harbor battlefield, the SCIAA team created a virtual tour of the naval battlefield: http://artsandsciences.sc.edu/sciaa/mrd/regsvys_chashbr_vt.html

First Stone Fleet

The Charleston Harbor was a lifeline for the Confederacy to bring in war materials and supplies and to exit with naval provisions and exports of cotton and rice. For that reason, the U.S. Navy was determined to stop the flow of goods through the two main entrances: Main Ship Channel and Maffitt's Channel, Spirek said.

As one measure to stop ships from running the Union blockade, the U.S. Navy bought 45 ex-whaling and merchant vessels, which they stripped of valuable materials and filled with rock so that once sunk they wouldn't let Confederate ships to pass.

While some sank in route or were diverted for other uses, 16 of the vessels were sunk Dec. 17 -- 21, 1861, by the U.S. Navy in the Main Ship Channel. Another 13 were sunk a month later, Jan. 20 -- 26, in Maffitt's Channel.

"For many years people surmised that they were sunk and broke apart and slipped under the quick sands as they called it and were gone and buried," Spirek said. "That is what I believed."

Spirek said magnetometers to detect ferrous materials such as iron or steel were of limited use because the ships were stripped of things like masts, anchors and chains, which could have been salvaged by the Confederates.

"We knew huge sections had broken and floated away. We also knew there would be a lot more rock than a typical ship because the cargo was rock. Large mounds of rock would be key in recognizing it was a stone fleet vessel," he said.

Overlaying old maps with new maps, they began their search. Using a magnetometer and a side-scan sonar, a device that uses acoustic waves to picture the ocean floor, Spirek and his team found the mounds that comprised the Stone Fleet.

Historical accounts indicated that the U.S. Navy sunk the ships in an organized checkerboard fashion so that ships couldn't travel straight through. That isn't what Spirek found.

"Everyone thought it was going to be very orderly, with wrecks strategically placed as Union reports and newspaper accounts had suggested. What we found was 15 ballast mounds, 14 of which were tightly packed together with the wrecks oriented along various points of the compass. We were surprised that the archaeological record shows a more happenstance distribution. I think it is still an obstruction but not quite how the historical records suggest," Spirek said.

The Second Stone Fleet remains somewhat elusive to Spirek's team. While they found four wrecks with large stones at the entrance of Maffitt's channel, Spirek said they appear to be boulder-laden flat-bottom boats used to construct the Charleston Harbor jetties that were built in 1878 -- 1896 rather than stone fleet hulks."

"Additional expansion of our survey coverage east and west, and perhaps north and south, should eventually pinpoint the remains of this stone fleet," Spirek said.

Confederate blockade runners

Despite the blockade of Union ships and sunken obstruction of the stone fleets, the majority of Confederate blockade runners were successful in getting in and out of Charleston Harbor.

"'The Northern Press' just railed at them for letting blockade runners through," Spirek said. "The Confederate blockade runners were low and painted grey to blend with the ground. They would steam quietly in, close to the beach during high tides on moonless nights, letting the lights of the Confederate armies on Sullivan's Island and the sound of the surf tell them whether they were too close and needed to bear left. Then they would turn on the juice if they started to get fired at. The advantage was completely with the blockade runner."

Spirek said while positions of the Union ironclads were well-documented, the locations of Confederate blockade runners were hazy and incomplete. He said they looked at 16 wrecks, 13 of which were blockade runners.

The team found remains of the blockade runners in two clusters with two outliers, all wrecked along Maffitt's Channel in attempts to elude the Union blockaders.

Close to the beach of the Isle of Palms is the wreck of the Georgiana, which led to the sinking of the Mary Bowers, found at the same site, followed by the Constance close by.

"While the vast majority made it through, the blockade runner had to be pretty fortuitous to avoid wrecking. The trio of the Georgiana, Mary Bowers and Constance just had bad luck," Spirek said.

A second cluster of seven wrecks were located at Fort Moultrie and Bowman's Jetty on Sullivan's Island, all victims of the inside blockade and composing the monitors and small launches.

Four wrecks were found buried under the beach on Sullivan's Island, covered by the build up of a century's worth of sand and sediment. With the help of USC archaeologist Jonathan Leader, the team tentatively identified two out of three blockade runners, most likely the Beatrice and the Flora on the beach, with the Celt remaining undetected. The Presto is under an area covered with trees and will be revisited in the winter.

A fluid battlefield

While the major findings of the survey were the First Stone Fleet and Confederate blockade runners, Spirek was able to locate several Union ironclad monitors by using previous survey reports and sonar technology and magnetometers.

These included the Patapsco, sunk by a torpedo obstruction near Fort Sumter; the Weehawken, south of Battery Wagner in the Main Ship Channel; and the Keokuk, an ironclad of experimental design that met its fate at the entrance of the Main Ship Channel after a severe pounding by Confederate artillery on April 7, 1863. Specific GPS coordinates were assigned to each wreck for future investigation.

The USC survey took nearly as long as the battle did more than a century ago, but the results are worth it, said Spirek.

"I've developed a passion for the Civil War through my work with the Hunley submarine and the Charleston Harbor project. We now know more about the history and the archaeology of this naval battlefield, what it means to people today and what it meant to the participants 150 years ago," he said.