Wirz was born in Switzerland in 1823 and moved to the United States in 1849. He lived in the South, primarily in Louisiana, and became a physician. When the Civil War broke out, he joined the Fourth Louisiana Battalion. After the First Battle of Bull Run, Virginia, in July 1861, Wirz guarded prisoners in Richmond, Virginia, and was noticed by Inspector General John Winder. Winder had Wirz transferred to his department, and Wirz spent the rest of the conflict working with prisoners of war. He commanded a prison in Tuscaloosa, Alabama; escorted prisoners around the Confederacy; handled exchanges with the Union; and was wounded in a stagecoach accident. After returning to duty, he traveled to Europe and likely delivered messages to Confederate envoys. When Wirz arrived back in the Confederacy in early 1864, he was assigned the responsibility for Andersonville prison, officially known as Camp Sumter.
While both sides incarcerated prisoners under horrible conditions, Andersonville deserves special mention for the inhumane circumstances under which its inmates were kept. A stockade held thousands of men on a barren, polluted patch of ground. Barracks were planned but never built; the men slept in makeshift housing, called “shebangs,” constructed from scrap wood and blankets that offered little protection from the elements. A small stream flowed through the compound and provided water for the Union soldiers, but this became a cesspool of disease and human waste. Erosion caused by the prisoners turned the stream into a huge swamp. The prison was designed to hold 10,000 men but the Confederates had packed it with more than 31,000 inmates by August 1864.
Wirz oversaw an operation in which thousands of inmates died. Partly a victim of circumstance, he was given few resources with which to work, and the Union ceased prisoner exchanges in 1864. As the Confederacy began to dissolve, food and medicine for prisoners were difficult to obtain. When word about Andersonville leaked out, Northerners were horrified. Poet Walt Whitman saw some of the camp survivors and wrote, “There are deeds, crimes that may be forgiven, but this is not among them.”
Wirz was charged with conspiracy to injure the health and lives of Union soldiers and murder. His trial began in August 1865, and ran for two months. During the trial, some 160 witnesses were called to testify. Though Wirz did demonstrate indifference towards Andersonville’s prisoners, he was, in part, a scapegoat and some evidence against him was fabricated entirely. He was found guilty and sentenced to die on November 10 in Washington, D.C. On the scaffold, Wirz reportedly said to the officer in charge, “I know what orders are, Major. I am being hanged for obeying them.” The 41-year-old Wirz was one of the few people convicted and executed for crimes committed during the Civil War.