Artifacts in the round: Archaeologists provide fascinating conservation update on shattered wagon wheel, Confederate munitions found in S.C. river cleanup

Wheel before treatment began and in shower stall more recently for cleaning, 6-pounder and 12-pounder shells (SCIAA); George Barnard photo of damage in Columbia after the Civil War (Library of Congress)

Maybe it’s just me (it probably is), but an unusual Civil War artifact undergoing conservation in Columbia, S.C., looks like a king crab or spider with a few of its legs missing.

There, I said it.

I have been fascinated by the remnants of a wagon wheel believed destroyed on Feb. 19, 1865, when Federal forces sacked the South Carolina capital and dumped captured Confederate ammunition and materiel into the Congaree River.

A metal detector first noticed the round object buried in the bed of the Congaree. Archaeologists surmised it was a just another rubber tire -- one of many found during an extensive river cleanup a few years back. More than 500 Civil War-related artifacts were recovered during the project, and this is among the most unexpected.

Jim Legg, public archaeologist for the South Carolina Institute for Archaeology and Anthropology (SCIAA), this month provided an update to the Picket on the conservation of the artifact and other pieces, none of which were believed to be fired. (At right, a sample of grapeshot and canister, SCIAA photo)

Hundreds of items emerged in 2022 and 2023 as crews removed century-old coal tar along the Congaree shoreline. Since then, Legg’s office and TRC Companies, a subcontractor for Dominion Energy, have been working to conserve items with a wide range of dates.

The completed military part of the collection will go to South Carolina Confederate Relic Room and Military Museum in Columbia for eventual exhibit.

The wheel hub, which has evidence of charring, will take at least another year to preserve. Archaeologists did not find any other wheels, metal hubs or large pieces of wood near the artifact.

“I have always thought the wheel was from (an) explosion. One thing that threw it off was that black rubber disk in the middle of the hub (left, TRC companies photo),” Legg wrote in an email.

"I finally just took it out to see what it was, and found that it was the rubber wheel from a 20th century kid's wagon. Either it floated into that location, or maybe one of the EOD (explosive ordnance disposal) guys picked it out of the junk pile and dropped it in there. It was a perfect fit.”

Even with that oddity, Legg is comfortable calling the fragment a casualty of Maj. Gen. William T. Sherman’s troops.

The features are consistent with a 1860s wagon wheel and it was found where at least one heavy wagon was blown to pieces.

“There is no record of any guns or gun carriages being destroyed/dumped in the river,” he added.

Something blowed up real good at river

Federal troops threw Confederate war materiel into the river after they took what they wanted before marching to North Carolina. Much of the state capital went up in flames, from a variety of sources, after its surrender.

Sean Norris, program archaeologist for TRC Companies, previously said of the wheel:

William Waud depiction of the burning of Columbia in 1865 (Library of Congress)

“The official records mention the explosion and the destruction of a wagon and a team of mules in a couple correspondences. It seems possible that what was left of the wagon after it was destroyed was thrown in the river along with everything else that was being dumped. There would be no specific reason for the wagon parts to be discarded elsewhere.”

The wheel at first was treated in a basic solution at the Relic Room before Legg moved it to his laboratory. Most of the recovered iron items considered the most important have been conserved.

The wheel has presented some challenges

Legg keep the wheel fragment in a shower stall for about a month during rinsing and hand cleaning. The artifact then went into a small tank, where it is undergoing polyethylene glycol (PEG) treatment for about another year.

“For size comparison this thing appears to be the same size as those seen on the NPS field artillery carriages -- fairly massive,” Legg wrote. In any case, they are the same basic design as a heavy wagon wheel hub.” (A gun carriage wheel at Chickamauga, Jim Legg photo)

I asked Legg whether the wheel has presented a conservation challenge.

“Yes, the fact that it is heavily encased in wrought iron hardware. Ideally, it would be cut apart, and the iron bands would be treated with electrolysis while the wood underwent the PEG process, then reassembled.” He said the cost for that would be enormous.

“I did a lot of manual cleaning of the iron before I started the PEG, but the bands are still fairly crusty. The iron will pretty much have to fend for itself, and I can only hope that it is not too unstable after the process is done. I can probably do some hand cleaning at that stage, perhaps with air abrader (a tool used to reduce corrosion), which will at least make it look better.”

A few items are distinctively modern

Norris said the project encountered Native American ceramics and projectile points and typical historic glass and ceramics that you would expect to find in river a flowing through a city.

The Relic Room exhibit on the Congaree finds will include a few non-Civil War items. Legg provided a photo (above) with a range: A brass hose nozzle, an iron sash weight, a Waterbury Clock Company winding key, an iron fork with wood handle (possibly Civil War), a silver plate fork from the Seaboard Coast Line Railroad, two .50-caliber BMG cartridges dated 1944, a pocket knife and a fire department button from the 1890s. 

Legg will produce a report on 1865 ordnance dump and a exhibit, possibly to open in 2027, at the Relic Room in Columbia.

“I have recently had some preliminary discussions with the museum about the exhibit, and the permanent curation of the collection there,” he said.

A group of 24-pounder and 12-pounder Confederate canister plates (SCIAA photo)

I asked Legg, who has helped produce three exhibits at the museum, how it might interpret the hundreds of historic artifacts found in the Congaree River cleanup.

“My thinking right now is to put the ordnance dump in the more general context of the Federal destruction of military resources in and around Columbia. I will also want to cover the pollution mitigation project itself, which was an amazing thing to see, even aside from the archaeology component.”

The Picket has reached out to the Relic Room for comment.

Recent view of the wagon wheel hub undergoing conservation in Columbia (SCIAA photo)