#18: The Libby Prison Escape — 1864
Union officers imprisoned at Libby Prison in Richmond secretly dug a tunnel from a rat-infested basement beneath the building toward a nearby tobacco shed. Working at night with improvised tools, they concealed dirt and protected the project from Confederate guards. On February 9, 1864, 109 prisoners crawled through the passage and escaped into Richmond. Fifty-nine eventually reached Union lines. It remains one of the largest successful prison breaks of the American Civil War.

