Camp Sumter was opened by the Confederacy in Andersonville, Ga., in March 1864. It was built on 16.5 acres between two mountains, and prisoners would scoop water from the “Stockade Branch” stream with tin cups attached to poles while remaining behind a “deadline.” Crossing the line meant instant death. The stockade’s pilings cramped the water flow and turned five acres of space into uninhabitable marsh, forcing prisoners to trudge through waist-high mud. The water became contaminated from human waste, laundered clothes and grease from the cookhouse. Sixty percent of the camp’s prisoners died, and with additional inmates the prison reached its peak population of 32,000 or one person per 25 square feet. More, in Tuesday’s column.