Libby Prison was a Confederate operated prisoner-of-war camp during the American Civil War. It had previously been a commercial building, but after reviewing its construction, guards considered the building inescapable and converted it into a prison. Like many camps, it was notorious for harsh conditions and overcrowding, and close to a thousand prisoners lacked food or proper medical care. The basement of the building was so destroyed by flooding and an extreme rat infestation that it was abandoned by prison staff.
In February of 1864 several men grouped together and began plotting their escape. Because of the perceived difficulty of escaping from the grounds, they decided to take advantage of the vacated basement. Eventually they discovered a chimney on the first floor which could give them access to the basement, and soon recruited more inmates to help them dig a tunnel out. The men worked in shifts, with each team enduring the dark, cold conditions while surrounded by hundreds of rats. After more than two weeks of digging with knives and other small tools, the men resurfaced in a lot adjacent to the prison. After securing the tunnel, they waited until nighttime before sneaking officers out in small groups. More than a hundred men had escaped through the tunnel before the guards began their morning patrols. Several of the remaining prisoners replaced the opening into the basement to conceal the tunnel for as long as possible.
The escapees weren’t discovered missing until later the next afternoon, when the Confederate staff tried to call roll. This gave the first of the jail-breakers nearly a day to cover ground. More than half of the prisoners were able to return to friendly territory, but the rest were captured or killed. This escape had a larger effect than just returning officers to their posts, however. Union morale was rejuvenated with such a victory, especially within the inmates who remained at Libby Prison.