From National Parks Traveler
By Jennifer Roberts October 29, 2025
NPS files
The USS Cairo, housed at Vicksburg National Military Park, is in danger of completely decaying if changes aren’t made to the way it’s being stored / NPS file.
A historic Civil War gunboat on display at Vicksburg National Military Park is in danger of completely decaying if changes aren’t made to the way it’s being stored, according to a 2025 study (attached).
The USS Cairo was one of the first steam-powered and ironclad ships used in the Civil War and sank in the Yazoo River of Mississippi in 1862 after a mine detonated and tore a hole in the port bow. The ship remained at the bottom of the river for nearly 100 years and was gradually buried with sediments. After the ship was recovered from the river, it remained exposed to the environment for over a decade.
Once funding was secured for preserving the ship at the Vicksburg National Military Park under the direction of the National Park Service in the 1970s, it was placed under a covered, open-sided structure, and the wood received various treatments to protect it from insects and decay.
However, the treatments haven’t entirely halted damage to the wood, which is showing signs of advanced decay. “Since the ship was stored unsheltered outside for many years after it was recovered, there was ample opportunity for fungi to colonize and decay the wood,” wrote the authors of the study.
Funded by the National Park Service, the recent study sought to determine the elemental composition and condition of the wood and to identify the fungi living in the structure of the USS Cairo.
To do this, lead author Robert Blanchette, a professor in the Department of Plant Pathology at the University of Minnesota, and three other researchers visited Vicksburg National Military Park to take samples directly from the decaying wood.
“To think about the history of it, and then to see that it's still there and you can look at it and learn more about it…it is really quite fantastic,” explained Blanchette during a recent interview. “It was great to be able to actually get into the ship and be there where back in 1861 they were using this in some of the rivers in the Civil War to fight off the other ships…it's quite exciting to visit the ship.”
The researchers discovered both soft rot and white rot fungi in the samples taken from the gunboat, some of which appear tolerant of compounds used to treat wood for preservation.
“We really don't know exactly how they do it and how they continue to grow there when other fungi can't,” said Blanchette. “More information is needed about [the fungi] to see how they do this, how do they tolerate these preservatives?”
In the meantime, Blanchette emphasized that the ship needs to be better protected. “The fungi are there. They’re continually attacking that wood. It’s going to gradually degrade more and more over time. For long-term preservation, it really is important to try to find funds to get the ship into a building that has environmental control. This would not only control the fungi because you’re controlling moisture, but you won’t have insect problems, and you won’t have that change in humidity occurring and temperature fluctuations that can cause problems with wood as it expands and contracts in different seasons.”
The results of the study were presented to Park Service staff at Vicksburg and are being evaluated. “I think that they would like to try to initiate getting a building for [the ship],” said Blanchette, though we were not able to confirm any current or future plans for the USS Cairo due to the ongoing government shutdown.
“We see that over a few decades, there has been deterioration and decay taking place in the ship, and it's only going to get progressively worse,” explained Blanchette. “The exact amount of time that's available is difficult to say, but for long-term preservation, something has to be done.”