On this day, American troops liberated Dachau. In 1942, Dachau built a crematorium; The concentration camp had been in operation for over a decade, with Jewish prisoners as the significant majority. Dachau initially imprisoned political prisoners and forced them in aiding to construct the camp. While in Dachau, prisoners were subjected to biological experiments against their consent, killing or disabling hundreds of prisoners. On the days leading up to liberation, thousands of prisoners were on a death march to Tegernsee, Germany. Upon the American arrival, prisoners greeted their rescuers with flags from the various Allied nations. The Nazi commanders sent a swath of prisoners to Dachau before its liberation. Records estimate that 30,000 people died in Dachau before the American liberation, which managed to rescue 30,000 prisoners.