On April 29, 1945, the U.S. Army ended the long nightmare at Dachau when it liberated 31,601 people from the concentration camp there. It was the first concentration camp established by the Nazis.

The camp was built just five weeks after Adolf Hitler became the Chancellor of Germany in 1933. Originally, it was used to imprison political opponents of the Nazis, such as Social Democrats and German communists. It was soon also used to hold “undesirable” elements of society such as homosexuals, Jehovah’s Witnesses, Roma, and repeat criminals. Over time, however, it came to primarily be used to house Jewish prisoners.

The people held in the Dachau concentration camp were used as slave labor to make weapons and ammunition for the German Army. They were also used as guinea pigs in human medical experiments, killing or crippling many of them. Many others were simply executed. Still, others died of the inhumane conditions that prisoners were forced to live in.

As the Allied forces started to make inroads into Nazi Germany, prisoners in concentration camps close to the borders were sent to Dachau. Still, the Allies pushed on, eventually reaching the camp on April 29 after a brief battle with the few SS guards who hadn’t already fled. What they found there was something straight out of a horror movie. 30 railroad cars were filled with decomposing bodies. The survivors were severely emaciated, on the brink of death. The American soldiers were so horrified at what had been done to the prisoners of Dachau that they machine-gunned the captured German guards.