The way back

Prisoner exchange is a recent innovation. For most of the history of war, a conquering army either enslaved or executed its captives. One of the earliest recorded incidents of exchanging captured soldiers occurred during the early years of the Roman republic. Around 300 BCE, the Romans swapped 1,700 captured Samnites for 310 mules.

Carthage pioneered parole programs for war prisoners. Its generals returned captured soldiers to their homelands provided they promised to never again fight against Carthage.

The Thirty Years War in Europe ended with a treaty called the Peace of Westphalia. Under the terms of the treaty, armies were to return captured soldiers to their home countries at the end of hostilities. In addition, the captors were to expect no ransom nor elaborate parole promises in exchange for the prisoners’ return.

The Peace of Westphalia is a precedent—and an important one. It’s the first document in history to formalize how belligerent nations should treat prisoners of war at the end of a conflict.

American Prisoners on Board a British Prison Ship. John Trumbull art via Fordham University

The first American POWs

During the American Revolution, the British didn’t consider the Colonial Army a legitimate combatant. To the British, the rebel colonists were traitors. And treason was a crime punishable by death in the United Kingdom.

The British imprisoned captured soldiers in massive prison ships in the East River. Because of their status as traitors, the soldiers were treated poorly. They were neglected, starved and beaten. When they died, their captors buried them along the shore.

More colonists died aboard these prison hulks than in every single battle of the American Revolutionary War combined. Some 8,000 soldiers died in battle, while almost 12,000 perished starving and diseased aboard the British prison ships.

Prisoner exchanges became increasingly common at the end of 18th century and into the 19th. The French and British armies traded soldiers during the Napoleonic Wars. The Americans and British used a formalized system of exchange during the War of 1812.

Union Maj. Gen. John A. Dix and Confederate Maj. Gen. D.H. Hill negotiated an agreement to exchange prisoners during the American Civil War. That agreement—the Dix-Hill Cartel—established clear rules for prisoner exchanges. It also assigned values to captured soldiers based on their rank. Under the Dix-Hill Cartel, two privates were worth one noncommissioned officer.

The trading system continued up the chain of command. Negotiators assigned a value in privates to each rank all the way up to general. Releasing a flag officer cost 60 privates.

Civil War POWs. Library of Congress photos

The Dix-Hill Cartel worked for 10 months then began to collapse. Neither side adhered to the spirit of the agreement. The Union routinely found they were fighting soldiers they had just released. Both sides questioned the treatment of their soldiers in captivity. The Confederacy refused to exchange black soldiers.

In occupied Louisiana in 1862, a Union general executed a civilian for desecrating an American flag. In response, Confederate president Jefferson Davis suspended the exchange of prisoners—and ordered the offending general hanged upon capture.

The Dix-Hill Cartel ended for good in 1863. The Confederacy’s notorious Andersonville prison opened in 1864. Now that prisoners had no path to freedom through a system of exchanges, Confederate prisons such as Andersonville swelled.

In time, Andersonville hosted 45,000 Union soldiers. Almost 13,000 of them died in prison. The camp was open a little over a year. The Union army liberated the prison in 1865. The federal soldiers were shocked by the brutal conditions they found there.

They took photographs—seen above—of the prisoners … and Harper’s Weekly published them. Washington and the public were horrified.

The Union arrested Maj. Henry Wriz—Andersonville’s commandant—and tried him for “conspiring ... to injure the health and destroy the lives of soldiers in the military service of the United States and murder, in violation of the laws and customs of war.” A military tribunal found Wriz guilty and hanged him.

But the Union also ran brutal prison camps. Elmira prison in upstate New York lost 3,000 of its 12,000 prisoners to malnutrition and exposure. Camp Douglas in Chicago also kept Confederate soldiers in awful conditions. The Union buried Camp Douglas’ 4,000 dead prisoners in a mass grave at Oak Woods Cemetery. It’s the largest mass grave in the western hemisphere.

POWs on the Bataan Death March. Air Force photo

The Hague and the horror

As the 19th century became the 20th, countries re-evaluated their treatment of war prisoners. The Hague Conventions of 1899 and 1907 laid the groundwork for what became the Geneva Convention. The 1929 Geneva Convention established parameters for the humane treatment of prisoners of war.

The World Wars tested these parameters. The German, French, British and Russian armies captured millions of soldiers during World War I. Many of them died in captivity, but conditions were not always terrible. The Red Cross and inspectors from neutral countries audited the prison camps of belligerent countries.

By contrast, World War II was not kind to prisoners of war. The Nazis were especially cruel to Russian soldiers, killing some 60 percent of those they they captured. Prisoner exchanges were rare. Work camps were common.

After Japan’s invasion of The Philippines, Japanese soldiers pressed American and Filipino POWs into the infamous Bataan Death March. Japanese guards subjected prisoners to food and water deprivation, forced labor, extreme beatings and beheadings.

Accounts of what was happening, relayed by Filipino resistance, horrified even the most battle-hardened allied commanders.

On the night Jan. 30, 1945, U.S. Army Rangers backed by Filipino guerrillas launched a rescue operation into Cabanatuan POW camp. They successfully liberated 489 POWs and 33 civilian prisoners. “No incident of the campaign in the Pacific has given me such satisfaction as the release of the POWs at Cabanatuan,” Gen. Douglas MacArthur said. “The mission was brilliantly successful.”

American soldiers endured grueling conditions during the Korean War. North Korean soldiers sent Americans on forced death marches, bound them in stress positions and withheld medical care.

North Korea’s Chinese allies fed their American detainees a steady diet of propaganda. They interviewed prisoners, asked them to fill out questionnaires and write essays and presented themselves as friendly, all in attempts to get the captive soldiers to defect.

The Chinese also tried to play on racial divisions, attempting to exploit the dissatisfaction of black soldiers by telling them that American society as it was would never treat them as equals—and that they would be better off becoming communists.

It’s possible that the United States left behind hundreds of American POWs after the war’s end. In 1996, The New York Times reported on newly declassified documents from the end of the war. The documents showed that the Pentagon knew about 900 living POWs still in North Korea in December 1953.

“In the past I have tried to tell Congress the fact that in 1953, 500 sick and wounded American prisoners were within 10 miles of the prisoner exchange point at Panmunjom but were never exchanged,” Col. Phillip Corso, a retired aid to American Pres. Dwight Eisenhower, told a House National Security subcommittee on military personnel in 1996.

In response to The New York Times report, the Department of Defense said it had no compelling evidence that any American troops remained after the war. Pyongyang also denies the existence of any remaining POWs.