Editor’s Note: This story is part of The Vicksburg Post’s continuing coverage of the 160th anniversary of the Siege of Vicksburg.

On June 25, 1863, a loud roar dominated the sounds of battle and dirt filled the air when Union forces blew up the Third Louisiana Redan.

The explosion was the result of a month-long project to put troops and 2,200 pounds of black powder under the Redan as a way to breach the Confederate lines and on to Vicksburg. It killed one unit of Confederate soldiers and a second explosion created a legend of a flying man.

The trench began in an area along the Jackson Road where the Illinois Monument now sits and a Union force under Capt. Andrew Hickenlooper was making its way to the Redan.

“Hickenlooper had been an artillery officer but had been tasked as the chief engineer of the 17th Army Corps,” said Andrew Miller, head ranger at the Vicksburg National Military Park. “His main focus was progressing this trench from the union lines where the Shirley House is today to the Confederate fortification known as the third Louisiana Redan and they had been incredibly successful.”

Work on the trench began at the end of May and by mid-June had reached the front of the fortification.

“The third Louisiana Redan was the only Confederate fort that did not have what they were referred to as a dry moat, but a trench in front of it, which meant that flat level ground went all the way up to the actual fort,” Miller said. “The principal engineering for defenses had that you had built obstructions in front of your fortification, including a trench that attacking forces would fall into, and there wouldn’t, there wouldn’t be that easy ability to climb the actual, uh, wall of the fort.”

The Redan’s construction allowed the engineers to dig from the Shirley House all the way to the front of this fortification, and then dig under it.

“The Confederates understood what the Federals were doing,” Miller said. “They could hear the picks and shovels as they were progressing underneath their fortification. They had a full understanding of what these federals were going to try to do.”

A Redan is a triangular-type structure with a point facing the enemy and an open rear.

The Confederates at the Redan completed the triangle by building what is known as a gorge wall that would enable them to hide as soon as they knew the Union troops were going to blow the fort. It would enable them to retreat and hide as soon as they knew the Federals would try to blow up the location. The wall provided protection and a defensive position to fight behind.

To find out where the federal troops were, the Confederates initiated counter mining; digging shafts into their fortification to locate the Federals’ tunnel.

The counter-mining, Miller said, was unsuccessful.

“So even up to July 25, the Confederates are hopeful that they can countermine and blow up and cave in the federal galleries that they’ve prepared under their fort,” he said.

The counter-mining was done by soldiers from the 43rd Mississippi, the famous Camel Regiment that had Old Douglas the camel.

“They are the ones that are trying to dig this counter mine,” Miller said. “And about a little before 3 p.m. all the work, all the shoveling and the picking and everything stops; the federals had placed 2,200 pounds of black powder in the galleries underneath the 3rd Redan.”

The Confederates retreated behind their wall and at 3:30 p.m. the powder was detonated.

“The fort was blown sky high,” Miller said. “We’re talking mules or artillery pieces, limbers, soldiers, the whole flown in the air.” The men of the 43rd doing counter-mining were killed.

The explosion was followed by an assault by Union troops but was driven back and counter-attacked by the 6th Missouri.

“After 24 hours of fighting the federal Army, after numerous assaults and reinforcements at this location retreated in dismal failure again, they had once again failed to try to take the Confederate position there,” Miller said.

“Blown to Freedom”

The Confederates began reinforcing the gorge wall at the Third Louisiana Redan.

Union soldiers continued digging under the Redan and on July 1 detonated a mine at the Redan, but did not attack.

“The July 1 mine explosion is the famous story about Abraham the slave,” Miller said. “The Confederates, not wanting to risk more soldiers, decided to put about 10 slaves into the Third Louisiana Redan to again continue counter-mining to find the federal location.”

When the July 1 mine was detonated, all but one of the enslaved people were killed. The one who survived was blown out of the fort and into the Union lines. The federal soldiers, when they saw him, said he landed out his head and got right back up and said he was all right.

“And this slave named Abraham became a celebrity for the next couple days in the Union siege lines because of the events that took place, and that he had been the ‘slave that was blown to freedom,’ as they called him,” Miller said.