What Happened When the Allies Discovered the Concentration Camps?

Sergeant John Lee had been at war for three years when his unit reached the outskirts of Ordruf on the 4th of April 1945. He had landed in Normandy, crossed the Rhine, and seen his comrades die in the snow during the Battle of the Bulge. He believed with the quiet certainty of someone who had seen too much that there was nothing left in this world capable of stopping him in his tracks. He pushed open the wooden camp gate and took three steps inside before stopping completely. Not because anyone ordered him to, but because his legs simply stopped working. What lay on the other side of the gate was not a battlefield, nor the destruction produced by bombs, nor the chaos left behind by a retreating army. It was something else entirely. It was meticulous order applied to the systematic extermination of human beings, and the results of that order were piled up in front of him in the form of bodies that seemed to have been manufactured to occupy the smallest possible amount of space. Ordruf was the first Nazi concentration camp liberated by American troops on the 4th of April 1945, twenty-three days before the war in Europe ended. At that moment, the American army had been advancing eastward for months, convinced that the worst thing it might encounter in its path was armed resistance. Instead, it found something for which there was no training, no protocol, and no language prepared in advance, a grim reality that would repeat itself across Europe.

Following that first opening of a gate, similar horrors were uncovered in the following weeks across dozens of places. The American army liberated Dachau on April 29, the British army liberated Bergen-Belsen on April 15, and the Soviet army had liberated Auschwitz on January 27. Majdanek had fallen the previous year in July 1944 when Soviet troops advanced so quickly from the east that the SS had no time to evacuate or destroy the installations. In each of those places, the soldiers who pushed open gates or cut through barbed wire found something that their minds, trained for war, took days or weeks to fully process. This is the story of those weeks, of what they found, of what they did, of what they could not do, and of the consequences of that encounter which did not end when the war ended, but continued for decades in courtrooms, in nightmares, in testimonies, and in the sustained effort to document what had happened before anyone could say that it had not happened.

The death train came first. Troops of the 42nd and 45th Infantry Divisions of the American Army were approaching Dachau on the 29th of April 1945 when they found a stopped train on the tracks running along the outer perimeter of the camp. Fifty freight cars stood with a damaged locomotive, showing no movement and making no sound. A soldier approached the first car and opened the side door to find dozens of corpses piled one on top of another, reduced by hunger and thirst to a thinness that made it difficult to recognize them as adult human bodies. The second car was the same, the third was the same, and all fifty cars were full. More than two thousand people had died on that train during the journey from the camps in the east, evacuated by the SS as the Allied advance made it impossible to keep the camps operating. They had been loaded without water and without food, packed so tightly that many could not even fall when they died because the surrounding bodies pressed against them and held them upright.

The doctor, Harold Porter, sent with the troops of the 42nd Division, preserved that moment in a letter to his family written that same night. Porter had taken part in the Normandy landings and had treated war wounds for months, yet he wrote that none of that had prepared him for what he saw in those cars. He noted that the image of the bodies piled up with open mouths and sunken eyes was something that would never leave his memory, no matter how hard he tried. That train, which historians would later call the Dachau death train, was the first object American soldiers encountered that day, and it was only the prelude to deeper horrors. Dachau had been the first concentration camp built by the Nazi regime, opened in March 1933 only weeks after Hitler came to power. It was not an extermination camp in the technical sense of Auschwitz or Treblinka, as it did not have large-scale operational gas chambers, but for twelve years it had functioned as a center of terror, forced labor, medical experiments, and systematic executions.

By the time of liberation, the camp held more than thirty-two thousand prisoners in facilities designed for far fewer. The final months of the war had turned overcrowding into something beyond any previous calculation, as transports from the east poured tens of thousands of people evacuated from other camps into Dachau as the front closed in. Captain William Cowling entered the camp minutes after the first soldiers cut through the barbed wire. Cowling was a staff officer, not a doctor, and his description of the camp interior in letters written to his family in the following days remains one of the most direct testimonies of what lay beyond the gates. He described mountains of bodies in the yards stacked as if they were firewood, and the crematorium with ovens still warm, alongside an adjoining room filled with corpses piled up to the ceiling waiting their turn. He described the smell, which was the first thing to reach visitors before anything could be seen, settling into clothing, hair, and memory for weeks.

Furthermore, he described the living: more than thirty thousand people who were technically still alive but had been reduced by hunger, disease, and years of systematic brutality to a state that made it difficult at first glance to distinguish them from the dead. They were skeletons covered with skin; some could not stand, some could not speak, and many, when they saw the American insignia, cried without their bodies having enough strength for the tears to fall. One prisoner ran toward the barbed wire as the troops approached, shouting in German that the Americans had arrived, only for an SS guard to shoot him in the back before he reached the fence. That was one of the last murders committed at Dachau before liberation, and the guard who fired was captured minutes later. What happened to that guard and to the other SS members whom American soldiers found at Dachau on the 29th of April 1945 is one of the most complex and best documented episodes of the final weeks of the war, beginning with something no military manual had contemplated.

What does a soldier do when he opens a gate and finds a crime of a magnitude for which there is no prior category in his experience? The first SS guards to surrender did so at Watchtower B, coming down with their hands raised and kneeling according to surrender protocol. An American soldier approached, drew his pistol, and executed them without prior orders and without trial at the very moment they were surrendering. It was the first in a series of acts that would be debated, concealed, investigated, and ultimately buried under the authority of General George Patton, who would become military governor of Bavaria and who personally blocked all formal investigations into what happened at Dachau in the hours after liberation. Lieutenant William Walsh captured four German soldiers and took them to the death train, forcing them to climb into one of the cars full of corpses. He kept them there for several minutes, locked inside with the decomposing bodies, before taking them out and executing them at point-blank range.

In another part of the camp, a nineteen-year-old machine gunner opened fire on a group of twelve German prisoners of war in a shed, and Colonel Felix Sparks found him afterward in a state of collapse, crying and repeating that they had tried to escape. No one believed him, and no one formally investigated it. In the first twenty-four hours after the liberation of Dachau, between fifty and one hundred and twenty Germans were executed by American soldiers, the range reflecting the fact that many of those acts were never officially recorded. Some soldiers handed weapons to the stronger prisoners, those who had survived in relatively better condition, and left them in charge of the captured guards. What followed was the direct revenge of men who had been dehumanized, beaten, tortured, and humiliated for years, carried out against those who had administered that dehumanization. Testimonies from the following days describe scenes inside the barracks and in the camp hospital that no official report recorded in full.

General Dwight Eisenhower, when reporting the liberation of Dachau, stated that thirty-two thousand prisoners had been freed and that American troops had killed approximately three hundred enemies, a phrase deliberately imprecise regarding how those individuals had died. Captain Cowling wrote to his family that he had seen his comrades execute SS guards who had surrendered and that he had watched it without feeling anything, noting that after seeing what was inside the camp, something in his moral system had stopped functioning normally. Bergen-Belsen was liberated by British troops on the 15th of April 1945, fourteen days before Dachau. The camp in northern Germany had not originally been an extermination camp, but an internment camp for prisoners of war and civilians, yet the final months of the war turned it into something entirely different. The mass evacuations from the east had poured tens of thousands of people in a state of extreme deterioration into Bergen-Belsen, and the camp’s supply system collapsed completely.

In the final months, there was practically no food or water, and typhus had spread throughout the entire compound. When troops of the British 11th Armored Division entered on April 15, they found approximately sixty thousand people alive in conditions that military doctors would describe as the worst they had seen in the entire war. There were also between ten thousand and thirteen thousand unburied corpses in the yards and barracks, some of them having lain there for weeks. Typhus did not distinguish between prisoners and liberators, and in the following weeks, several hundred more people died of disease despite medical efforts because their physical deterioration had reached a point at which medical care arrived too late to reverse it. One of those who died at Bergen-Belsen before liberation was Anne Frank, who had arrived at the camp from Auschwitz in October 1944 at the age of fifteen and died of typhus in early 1945, weeks before the British arrived.

Her father, Otto Frank, was the only member of the family to survive, and the diaries Anne had written while in hiding in Amsterdam were found after the war and published in 1947, selling more than thirty million copies in seventy languages. The war correspondent Richard Dimbleby entered Bergen-Belsen with the British troops and recorded a radio report that the BBC initially refused to broadcast because it considered the content too extreme to be believed. Dimbleby insisted, saying he would sign his name to every word and personally answer for the truth of everything he said, and the BBC finally broadcast the report, in which Dimbleby described the bodies, the smell, and the survivors walking among the dead with no apparent ability to process the difference. Meanwhile, the Red Army had reached Auschwitz on the 27th of January 1945, almost three months before the Western liberations, finding that the SS had had weeks to act, burning archives in massive quantities, blowing up three of the four crematoria, and evacuating prisoners who could walk in death marches toward the west.

What they could not destroy was simply too large, and when Soviet soldiers of the 60th Army entered the camp, they found approximately seven thousand prisoners who had been abandoned because they were too sick or too weak to be evacuated. They found the gas chambers, some demolished but still recognizable, alongside warehouses the SS had not had time to empty, containing more than seven tons of human hair packed to be sent to textile factories in the Reich, eight hundred and fifty kilograms of eyeglasses, hundreds of thousands of prosthetic limbs, and tens of thousands of pairs of shoes and suitcases with names written on the outside. Lieutenant Anatoli Shapiro later described the instant in which he realized that what he was seeing was incompatible with any category of wartime experience he knew, noting that what distinguished Auschwitz was not the number of victims, but the organization and visible evidence that what had happened there had been planned, administered, documented, and carried out as an industrial process.

Eisenhower visited Ordruf on the 12th of April 1945, eight days after the initial liberation, accompanied by generals Patton and Bradley. Before entering, Eisenhower told his escort that it was important for the highest-ranking military commanders to see personally what was there because he foresaw that in the future there would be people who would claim that the stories about the camps had been exaggerated or invented. What he saw at Ordruf was enough for him to issue an order that would change the nature of the historical record, instructing journalists, photographers, and cameramen to be sent to all liberated camps with orders to document absolutely everything. He also ordered delegations of congressmen and British parliamentarians to be taken to visit the camps in person, and he ordered German civilians from the cities and towns near the camps to be forcibly taken inside to see with their own eyes what had happened only a few kilometers from their homes.

That last order produced scenes that military photographers captured with a disturbing clarity, showing columns of German citizens walking among the bodies in the campyards, some staring straight ahead, some crying, and some insisting with desperation that they had known nothing. The question of what German civilians knew is one of the most debated issues in the historiography of the Holocaust, but Eisenhower wanted to document not only the magnitude of the crime, but the impossibility of ignorance. The correspondent Edward R. Murrow visited Buchenwald on the same day Eisenhower was at Ordruf, and his report from Buchenwald, broadcast by CBS three days later, began with a warning that what he was about to describe was difficult to hear. He described the barracks, the bodies, and the living men leaning against the walls, stating that death in Buchenwald had no logic he could recognize as human, generating a massive volume of correspondence from listeners who struggled to process the broadcast.

The survivors who were able to speak began to give testimony in the days and weeks after liberation, constituting the part of the historical record that documents and photographs cannot provide: the internal experience of what it had been like to live in those places. Primo Levi was liberated from Auschwitz by the Soviets in such poor condition that it took him months to return to Italy, and he began writing If This Is a Man that same summer, describing the arrival at the camp, the tattooing of the number on the arm, the systematic destruction of personal identity, and constant hunger as the organizing axis of all mental life. Elie Wiesel was liberated from Buchenwald at the age of sixteen, having lost his mother and younger sister at Auschwitz and his father at Buchenwald just weeks before liberation. He did not write about those experiences for ten years, but when he finally did, the text he produced was called Night, becoming one of the most widely read testimonies of the twentieth century.

The testimonies of the liberating soldiers have one feature that distinguishes them from those of the survivors: the shock without preparation. The survivors had arrived at horror gradually through a process of progressive destruction, whereas the liberating soldiers arrived at the conclusion in seconds by pushing open a gate. Sergeant Horace Greinfeld described decades later what happened in his mind when he entered Dachau, noting that the first reaction was automatic rejection and an instinctive denial that lasted approximately thirty seconds, followed by the collapse of a category as the part of his mind that classified things into possible and impossible stopped functioning. Many soldiers developed severe post-traumatic stress disorder directly related to the liberation of the camps rather than previous combat, experiencing psychological collapse, nightmares, inability to sleep, and panic reactions to situations that had no objective connection to what they had lived through.

The documentation process ordered by Eisenhower produced an archive of a richness and completeness that has no equivalent in the history of any other war crime, with military photographers taking tens of thousands of photographs, cameramen filming hours of footage, and journalists producing widespread reports. Among those photographers was Margaret Bourke-White, sent by Life magazine to Buchenwald in April 1945, who later described that she had deliberately forced herself to see the world through the camera’s viewfinder because that small rectangle made it possible to keep functioning. Meanwhile, the Red Army made decisions after the liberation of the eastern camps that western historiography took decades to analyze fully, keeping some sections of Sachsenhausen and Buchenwald in operation as Soviet detention centers for German officers and people considered politically hostile, where tens of thousands of people died between 1945 and 1950.

The Nuremberg trial began on the 20th of November 1945, six months after the liberation of the last camps, bringing twenty-four of the principal surviving leaders of the Nazi regime before an international tribunal at the Palace of Justice in Nuremberg. The concept of crimes against humanity was developed and formalized specifically for that trial because the crimes to be judged did not fit into any pre-existing legal category, establishing that certain crimes are offenses against all humanity regardless of state borders. The defendants responded in various ways, with some invoking obedience to orders, some claiming ignorance, and figures like Hermann Göring arguing that Germany had the right to do what it had done. Twelve of the defendants were sentenced to death, ten were executed on the 16th of October 1946, and Göring killed himself the night before by biting into a cyanide capsule, while Martin Bormann was sentenced to death in absentia and later confirmed to have died during the final days of the battle for Berlin.

Following Nuremberg, judicial processes regarding other perpetrators were often fragmented and delayed. Adolf Eichmann fled to Argentina in 1950 using false documents, lived under the name Ricardo Clement, and was identified and captured by the Mossad in 1960 before being tried in Jerusalem in 1961 and executed in May 1962. Josef Mengele fled to Argentina in 1949, moved through Paraguay to Brazil, and lived until his death by drowning in 1979 without ever appearing before any court, remaining the best-known symbol of partial impunity. Klaus Barbie, head of the Gestapo in Lyon, was protected after the war by American intelligence services before being extradited from Bolivia to France in 1983, where he was tried and sentenced to life imprisonment, dying in prison in 1991. Simon Wiesenthal, a survivor of several camps, dedicated the rest of his life to documenting the identity and whereabouts of Nazi war criminals who had evaded justice, contributing directly to the capture of more than a thousand people over the following decades.