In June 1864, a group of soldiers from Company I, 19th Massachusetts Infantry Regiment are captured at the Battle of Cold Harbor in Virginia and transported by train to Georgia, where they march to the harsh military prison known as Camp Sumter. At the gate, Col. Chandler, William H. Macy, commands with a steady, imposing presence, while Captain Henry Wirz Jan Tříska runs the camp with a rigid, calculating calm. Wirz outlines the grim reality: escape is nearly impossible thanks to his scent hounds, and a prisoner exchange is anticipated but far from certain. The newcomers quickly sense the bleak odds and the oppressive mood that will define their stay.
Early on, the prisoners cross paths with Dick Potter Gregory Sporleder, a former comrade captured at Antietam, who becomes a wary mentor of sorts. Potter has seen the worst the camp has to offer and warns them about the Raiders, a ruthless faction of internees who prey on the vulnerable to hoard supplies. He pulls back the veil on the camp’s harsh reality: there is barely enough shelter, water, and food to go around, and the guards include teenagers and older men who take grim delight in coercing prisoners toward the dangerous “dead line” and then shooting them as a warning. The atmosphere is tense, with Wirz’s tight control balancing on a knife edge as a Confederate Colonel audits the operation and chastises Wirz for the squalor, a moment Wirz greets with deflection and a quiet request for a promotion recommendation.
A stubborn group of prisoners from the 19th Massachusetts aligns with other internees who are secretly digging a tunnel beneath the stockade wall. The plan is perilous and nearly clandestine, but the work progresses as the tunnel nears completion. Then the Raiders strike, and Potter is killed in a brutal flare of violence. One prisoner attempting to inform the guards in hopes of a reward is seized, and the taunting stigma of “TT”—tunnel traitor—carved into his forehead marks the price of betrayal and fear. Despite the danger, the tunnel is completed, and the escape unfolds with a mix of courage and catastrophic losses; most who attempt it are killed or captured, and a portion are punished by standing stocks as a brutal reminder of the consequences of resistance.
The escalating tension within the camp erupts into a riot as disparate prisoner groups rally to challenge the Raiders. A makeshift court is proposed to address the raiders’ leadership, and Captain Wirz approves an internal, prisoner-run trial. A jury of fellow internees convicts the six Raider chiefs to death by hanging, while the lower-ranking raiders face a brutal gauntlet as punishment. With the Raiders’ power diminished, life inside Camp Sumter briefly relaxes into a fragile order.
As time passes, new internees arrive with tales of another escapee who reached General Grant, who then rejects any broader prisoner exchange due to the Confederacy’s treatment of Black Union soldiers. The camp’s morale shifts as a Confederate officer arrives with a blunt offer: fight for the Confederacy in exchange for freedom. The men of the 19th Massachusetts, along with others, stand in formation, turn their backs, and refuse the deal—an act of solidarity that signals a deeper resolve to endure.
Yet the toll of hunger, disease, and the rigors of confinement grows heavier. Starvation compounds the dwindling supplies, and thousands never leave the prison walls. Eventually, Captain Wirz announces that an exchange will proceed, and the surviving prisoners begin to depart Camp Sumter, filing past their fallen comrades on the way to the trains that will carry them away. The film closes with a somber coda set against the present-day Andersonville National Cemetery, a stark reminder of the lives lost and the enduring memory of those who endured the camp’s horrors.
