In this undated photo provided by the Library of Congress Gen. William Tecumseh Sherman poses for a photo. On Nov. 16, 1864, Sherman watched his army pull out of Atlanta, and marched with 62,000 veteran troops to the Atlantic coast at Savannah, conquering territory and making a point to the enemy in what would be known as Sherman’s March to the Sea during the American Civil War. (Library of Congress via AP)

Drunk and rowdy, Gen. William Tecumseh Sherman’s troops captured South Carolina’s capital on Feb. 17, 1865. It was nearing the end of the Civil War, and Sherman’s plan was to destroy the state where secession began.

“The truth is, the whole army is burning with an insatiable desire to wreak vengeance upon South Carolina,” Sherman wrote to Gen. Henry W. Halleck. “I almost tremble at her fate, but feel that she deserves all that seems in store for her.”

Sherman’s 60,000-man army torched Columbia in retaliation for seceding from the Union. The blaze, which he later blamed on a Confederate general he said left cotton bales in the streets, destroyed a third of the city. Sherman’s troops made off with the Confederate armory. They confiscated cannonballs, rammers, sabers and bayonet scabbards. And, on their way out of town, they dumped whatever they couldn’t carry into the Congaree River.

Gervais Street Bridge, Gervais Street spanning Congaree River, Columbia, Richland County, S.C., in 1986. (Jack E. Boucher/Library of Congress)

Amid a massive toxic tar cleanup, historians have found possible evidence of the loot using sonar and metal detectors near the Gervais Street bridge in downtown Columbia, the city’s State newspaper first reported over the weekend. The munitions, if indeed they are munitions, are said to be buried in 40,000 tons of black tar that spilled into the river several years ago from a now-defunct power plant. Historians are trying to find the best way to retrieve the stash, with explosive experts on hand.

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“Hopefully, none of it is going to blow up,” Joe Long, curator of the Confederate Relic Room and Military Museum, told the newspaper.

Researchers located more than 200 sites in the two-foot-thick oil sludge as “exhibiting signature characteristics that could be associated with ordnance.”

The tar was discovered in 2010 near the governor’s mansion by a local kayaking instructor — and the city launched a $18.5 million cleanup led by SCANA, an energy company.

“We don’t have any direct knowledge of ordnance,” Tom Effinger, SCANA’s director of environmental services, told the State. “We don’t know if it’s hubcaps or what is there.”

However, the newspaper recently obtained a report to SCANA from Tidewater Atlantic Research, a historical and archaeological firm, about the weapons.

“It has been confirmed that in 1865, during the Civil War, live munitions and other articles of war produced by the Confederacy were dumped into the Congaree River near the Gervais Street bridge by Union forces,” it stated.

For more than a century, bits and pieces of the Confederate materiel has been recovered. After the war, locals would jump into the river to retrieve cannonballs and shells. In the 1930s, political leaders organized a dive that turned up a half-dozen cannonballs, more than 1,000 rifle balls as well as time-fused bombs and an ax, the State reported. In the 1970s and 1980s, private excavations found additional items.

It’s unclear exactly how much there is to find, but an inventory taken 150 years ago lists 1.2 million ball cartridges, 100,000 percussion caps, 26,000 pounds of gun powder, 4,000 bayonet scabbards, more than 3,000 sabers, more than 1,000 soldiers’ knapsacks and nearly 60 tents, according to the newspaper.

“I’m sure there will be some interesting items,” South Carolina’s underwater archaeologist James Spirek told the State. “I don’t anticipate huge volumes.”

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As dawn broke on Feb. 16, 1865, Union soldiers moved in on the water’s edge, across from Columbia on the other side of the Congaree, according to the city’s history. When the troops discovered the Gervais Street bridge had been burned by the rebel army, they began firing cannons on the town. They bombed the railway station and the state house, which was under construction at the time.

Sherman sent his men to the only other bridge on the Broad River and, as the soldiers approached, the Confederates burned the bridge to stop them. Sherman’s army waited until nightfall, then crossed the river in pouring rain. Later that night, much of the city was aflame.

Historians are excited about the pieces of history they might find buried deep in the Congaree.

“It’s really going to help up interpret what was a defining point for Columbia’s history and, really, South Carolina’s history,” Long told the State.

h/t The State