During my road trip through Florida, I visited the Andersonville National Historic Site in Georgia.
Andersonville was a Confederate prisoner of war camp during the Civil War. It was overcrowded to four times its capacity. It had inadequate food and water supplies and the prisoners suffered immensely. Of the approximately 45,000 Union prisoners held at the prison during the war, nearly 13,000 died.
The national cemetery at Andersonville contains 13,714 graves, of which 921 are marked "unknown".
In the summer of 1864, tens of thousands of Union prisoners of war were dying of thirst at Andersonville. Suddenly, a spring erupted from the ground within the stockade. The prisoners credited its appearance to divine intervention, and Providence Spring became part of the established lore of the Civil War.
After the war, the commander of the prison was tried for war crimes--and was executed.