This year marks the 75th anniversary of the American liberation of Dachau. On Sunday, April 29, 1945, the U.S. Seventh Army’s 45th Infantry Division freed the concentration camp located on the outskirts of Munich. American soldiers had already encountered Nazi bestiality three weeks earlier, when they liberated Ohrdruf, a subcamp of Buchenwald near Weimar. But the sheer atrocities they encountered at Dachau—39 railway boxcars loaded with decaying, skeletal corpses, buildings in the camp stuffed with dead bodies—exceeded the imagination.

General Eisenhower had toured Ohrdruf in mid-April and ordered journalists to document what they saw there for posterity. The brutal images soon made their way to the United States. Today, say the word “concentration camp” and many immediately think of Auschwitz. That camp, which has become the worldwide symbol of “the Final Solution of the Jewish Question” (though it was initially established for Polish Christian prisoners and St. Maximilian Kolbe was martyred there), had been liberated by the Red Army on Jan. 27 earlier that year.

Dachau was for the American army what Auschwitz must have been for the Soviets. For many years it remained in the American mind the epitome of Nazi brutality and crimes. Dachau was especially notorious for its “medical research.” German scientists used prisoners—mostly Polish priests and Soviet POWs—in their decompression and cold-water experiments. Looking for ways to save German airmen who were shot down or ditched in the North Atlantic, the Germans subjected Dachau’s inmates to decompression and mid-winter immersion in ice water to ascertain for how long subjects could survive at extremely low body temperatures—and how the victims might be revived.

American popular culture’s identification of Dachau with Nazi brutality, especially in those postwar years, deserves attention. Consider a notable example: “Deaths-Head Revisited,” a 1961 episode from Rod Serling’s Twilight Zone series.

The story is set in Dachau. Gunther Lutze, a former SS captain who conceals his identity as “Schmidt,” returns to visit his old stomping ground. Not finding anyone to accompany him, he enters the “former” camp facility alone. (The first time I visited Dachau in 1989 and asked how to get to that “concentration camp,” I was firmly told how to reach the “former” camp). As Lutze wanders down memory lane, he encounters Alfred Becker, a victim of Lutze’s sadism. As it dawns on Lutze that he had murdered this particular research subject, Becker and the other ghosts of Dachau sentence him, as a matter of “justice,” to experience mentally what he had wreaked on the prisoners physically, driving him insane. A doctor is summoned and, as Lutze is taken away to a mental institution, the doctor gazes at the remains of the camp and asks, “Dachau: Why does it still stand? Why do we keep it standing?”

Serling’s bracing monologue at the end of the episode answers that question:

There is an answer to the doctor’s question. All the Dachaus must remain standing. The Dachaus, the Belsens, the Buchenwalds, the Auschwitzes—all of them. They must remain standing because they are a monument to a moment in time when some men decided to turn the Earth into a graveyard. Into it they shoveled all of their reason, their logic, their knowledge, but worst of all, their conscience. And the moment we forget this, the moment we cease to be haunted by its remembrance, then we become the gravediggers. Something to dwell on and to remember, not only in the Twilight Zone but wherever men walk God’s Earth.

The focus of contemporary Holocaust education is the Nazi campaign to exterminate the Jews, as it should be. We can never forget that the Jews occupied a special rung on the Nazi ladder of sub-humans, the Untermenschen. To be a Jew was to be sentenced to death. Period. Full stop.

Had the regime not been defeated, however, it’s likely that other groups would have come into full view of the Nazi killing scope. In the Majdanek concentration camp in Lublin, Poland, visitors can peruse Nazi plans from 1943-44 to expand the camp four times in size. By that time a considerable part of European Jewry had already been killed. But because even in killing, the Nazis were economically calculating, it takes little imagination to see that Poles could have been the next Untermenschen, the next Lebensunwertes Leben, or “life unworthy of life.”

This phrase, “life unworthy of life,” did not come from Hitler or Goebbels, but from two German professors—of law and of psychiatry—who published a book of that title in 1920 (13 years before Hitler came to power), to justify why some people were better off dead. The Nazi killing machine gave eugenics a bad name, but something else we should not forget is that eugenics had a notorious American endorsement. In 1927, seven years after Karl Binding and Alfred Hoche published their thoughts on disposable lives, an associate justice of the United States Supreme Court opined, in defense of compulsory sterilization, that “[t]hree generations of imbeciles are enough.” (That decision, Buck v. Bell, has never been overruled.)

George Santayana warned that “those who cannot learn from history are doomed to repeat it.” If the Nazi death cult is not to be dismissed as an historical anomaly or reduced to warnings about racial or ethnic prejudice, then Dachau must remain an object lesson for our day. When life ceases to be sacred, when it no longer is an inalienable right given by the Creature but a negotiable human choice, we are on the road to Dachau.

And we are very much on that road today. Whether it be refined abortion techniques, embryonic experimentation, or suicide-with-medical-accomplice, our reason, our logic, and our knowledge are being put in the service of deadly ends. Seventy-five years after the liberation of Dachau, have we become the gravediggers of our day?