The Nazis cast a wide net when they set out to rid German society of everyone who didn't fit Adolf Hitler's vision of a "master Aryan race." Targeted groups included not only Jews, but also Gypsies, carriers of hereditary diseases and anyone whose behavior was deemed "aberrant."

Homosexuals were among the last category, and the little-told story of their maltreatment by the Nazi regime is documented in a riveting exhibit now showing at the American-Jewish Museum in the Jewish Community Center, Squirrel Hill.

"Nazi Persecution of Homosexuals 1933-1945" is a traveling project of the U.S. Holocaust Memorial Museum. The formal opening will be Dec. 3 at 7 p.m. in the center's Levinson Hall, with a keynote speech by the exhibit's curator, Ted Phillips.

Related events will take place throughout the run, which ends Feb. 6. These include a program on discrimination in Pittsburgh, focusing on gay, lesbian, bisexual or transgender youth, with filmed interviews and discussion (7 p.m. Dec. 17, Levinson Hall).

"This exhibit is unprecedented," said Edie Naveh, director of the Holocaust Center of Pittsburgh, which is co-sponsoring the show. "There's never been anything else like it, certainly not in this country."

Using reproduced photos, papers, police reports, first-person accounts, artwork and a connecting historical narrative, the exhibit traces the roots and progression of Hitler's anti-homosexual campaign.

By the end of the war, more than 100,000 men had been arrested. Some 50,000 served prison terms, and an unknown number were sent to mental hospitals. Others, maybe hundreds, were castrated. Somewhere between 5,000 and 15,000 were sent to concentration camps, where many died from starvation, disease, exhaustion and beatings and murder.

At the core of this anti-homosexual obsession was a nationalist fear: Germany had lost 2 million men during World War I, and many were panicked that the Aryan "Volk" (people) might not survive.

Gay culture had been flourishing during the Weimar era, when Berlin's 350,000 homosexuals visited same-sex clubs, bars, cafes and dance halls. This culture was seen as threatening to what the state called the "disciplined masculinity" of the nation.

In reaction, the Nazis seized on an old provision in the criminal code, dating to 1871. The law, known as Paragraph 175, made homosexual acts illegal, but the Reich made the provision broader and harsher, giving legal cover the campaign of persecution and murder that would follow.

Homosexuals were denounced as "antisocial parasites" and "enemies of the state." Lesbianism was also outlawed, but women were not much targeted.

From 1935 on, the noose kept tightening. Heinrich Himmler decreed formation of the Central Office for Combatting Homosexuality and Abortion. Increased surveillance led to denunciations, arrests and convictions, transfer to concentration camps and persecution in Nazi-occupied territories.

Despite a 1933 agreement between Hitler and the Vatican, Commander Himmler launched an investigation of the Catholic monastic orders, calling the priesthood "a homosexual, erotic male organization" that had been "terrorizing humankind for 1,800 years." Some 2,500 clerics were arrested, and 64 were convicted.

The Nazis also targeted homosexuals within the military, forcing them to serve and then using them as cannon fodder on suicide missions.

The discrimination outlasted the war by at least a half century. Men, and some women, who had been prosecuted and punished for their presumed homosexuality were not permitted to receive reparations, unlike other persecuted groups.

The first public commemoration of this chapter of German history took place in 1985, in a speech by West German President Richard von Weizsacker. Even then, Paragraph 175 was not abolished until 1990.

The Holocaust Center is offering docent tours of the exhibit for students in grades nine and up, as well as to other groups.

For a full list of related programs, visit holocaustcenterpgh.net. To schedule a tour, call the center at 412-421-1500. More information also is available at ushmm.org/museum/exhibit/online/hsx.