Why did the response of the soviet soldiers to auschwitz differ from the response of american soldiers to dachau? why did both the americans and british bring german survivors to the camp sites?

In January 27, 1945, the Soviet army entered Auschwitz and liberated more than 7,000 remaining prisoners who were mostly ill and dying. The Soviet soldiers were considered to be the first to liberate concentration camp prisoners in the final stages of the war.

Meanwhile, in April 1945, the American soldiers have also liberated prisoners from the major concentration camps, including Dachau.

The difference is the method of liberation. The Soviets are the first to approach the Nazi camp, reaching Majdanek. On the other hand, it was the underground prisoner resistance organization who seized control of Buchenwald to prevent anymore violence from the retreating guards. 

The Americans and the British brought the Germans to their respective camps to serve as prisoners of war.

Though these 425,000 Germans are prisoners, the Americans treated them fair and just, that most prisoners found their living condition to be better than the civilians in cold-weather flats in Germany. They are even provided with writing materials, art supplies, woodworking utensils and musical instruments.

On the other hand, the Soviet has captured almost 3 million Germans that they kept as prisoners at their camps. Of these, almost 1 million were recorded to have died under the Soviet custody, due to diseases, starvation and lack of medical care.