JOHNSON ISLAND, Ohio — Civil War history hides under a grassy field tucked amid barren trees on Johnson Island, a patch of land in Sandusky Bay where captured Confederate prisoners were confined 150 years ago.
From 1862 to 1865, more than 10,000 Confederate inmates were held in the Johnson Island Civil War Prison. Some never left: about 250 white stones — a few with the stark engraving “unknown” — mark the nearby cemetery where men from Mississippi, Missouri, North Carolina, Tennessee, and other southern states found their final resting place.
Save for a modest plaque designating the National Historic Landmark, there are few obvious traces of the nearly 17-acre former prison on the island’s eastern side.
But when the weather warms, schoolchildren, college students, and researchers restart the painstaking archaeological excavation begun more than two decades ago.
First, volunteers are needed to clear branches felled during the harsh winter and start work on a trail along the property. Saturday marks the ninth year the prison site has participated in the Civil War Trust’s Park Day, an event that draws thousands of volunteers to help maintain about 100 war sites across the country.
“A lot of these places have fairly small staff, and coming out of a winter, especially one like this past one, you have really major needs for upkeep and capital-improvement projects,” said Mary Koik, spokesman for the Civil War Trust in Washington. “Something like this really gives you the bodies to be able to do a new walking trail or repair your fences.”
The island-work bee attracts about 80 volunteers from northern Ohio and even some surrounding states, and the military prison site is the only Ohio location participating in this year’s Park Day.
Under the watchful eye of David Bush, chairman of the nonprofit historic preservation organization Friends and Descendants of Johnson Island Civil War Prison, and director of Heidelberg University’s Center for Historic and Military Archaeology, work has progressed slowly to dig up and identify old objects buried there.
Bits and pieces pulled from the ground tell parts of the Civil War story: Nails, medicine bottles, ceramic plates and mugs, chimney bricks, chamber pots, and pieces of hard rubber carved by prisoners.
This season, archaeological work will continue at Block 8, a former housing block where about 250 prisoners were held.
A two-story wooden building measured about 125 feet by 29 feet, and through its wooden-floorboard gaps fell debris researchers now try so carefully to collect.
After the war, the prison site was farmed until about 1950, then abandoned. Trees took root and the prison’s precise spot faded from memory until Mr. Bush began his research.
A white tent stretches over the site where archaeological digging will take place this season, beginning next week with a program for middle and high school students and, in the summer, a five-week field school.
Mr. Bush and a couple of Heidelberg students worked Wednesday to ready the area. They traipsed over a mud-splotched tarp spread beneath the tent, sorting buckets and preparing the site.
Seeing youngsters learn about archaeology is a highlight for Felicia Konrad, a Heidelberg senior from North Baltimore majoring in history and archaeology.
“I’ve seen so many little kids find something and
be like, ‘Oh, this is really cool,’ even if it’s just a piece of window glass,” she said.
For Mr. Bush, the site’s allure traces its rich history, preserved in both written accounts and in the dirt to be scraped away and examined.
“It’s just that every year we discover more interesting things,” he said. “It’s got a great historical record; it’s got a great archaeological record.”
The Union located the prison there because the island was easier to defend than a mainland site, but it was close to Sandusky for access to supplies. Originally intended to house Confederate enlisted men as well, it soon held only officers.
Prisoners captured in battles such as Gettysburg and Vicksburg were brought to Johnson Island by train and boat. The prison’s population peaked at more than 3,200 men during the latter stages of the war.
Preserving the history and educating people about the site’s importance is the aim of the Friends and Descendants group, which will be recognized during the Park Day event with a Heritage Award from the Ohio Civil War 150 Advisory Committee. The committee, formed to recognize the war’s milestone anniversary, will give out three such awards this year.
The site’s role in Civil War history intrigues Bob Minton of Fostoria, an advisory committee member and trustee for the Friends and Descendants group. He will present the award Saturday.
“It’s fascinating to me because, first of all, we know that in that area, for several years, several thousand Confederate officers were there; and a lot of these guys were the cream of southern society,” he said. “They were walking that very ground every single day, and to me that makes it very unique.”