On this day in 1945, American troops liberated Dachau. The concentration camp had been in operation for over a decade since then, with Jewish prisoners comprising a significant portion of the inmates since 1938.In the early years of Dachau, prisoners were forced to aid in constructing it. This included a crematorium area that was built in 1942. Prisoners were also subjected to experiments involving altitude sickness, hypothermia, malaria, and tuberculosis; those experiments killed or disabled hundreds of prisoners.In the days leading up to Dachau’s liberation, thousands of prisoners were forced on a death march to Tegernsee, many miles to the south. Shortly after, many of the camp’s guards left; those who remained prepared to surrender.When the first American scouts and soldiers arrived, they were greeted by a patchwork of flags from various Allied nations; the prisoners had pieced them together out of their meager supplies. The camp was filled with corpses and trash, which was exacerbated by the number of prisoners that had been transferred to Dachau from other camps before liberation.When the German guards presented themselves for surrender, many were killed by the liberating soldiers. United States General Dwight D. Eisenhower noted that 300 camp guards were neutralized, and over 30,000 prisoners were freed. In the days following liberation, prisoners were slowly nursed back to health, having been starved for so long that food had to be reintroduced gradually.It is now estimated at least 30,000 people were killed in Dachau in the years before its liberation, with even more shipped off to their deaths at other camps.