Historian unearths one of America’s earliest gay rights activists.

A crowd gathers to witness thousands of books, considered to be "un-German," burn in Opera Square in Berlin during the Buecherverbrennung book burnings on May 10, 1933.(AP file)

In May 1933, the Nazi-sympathizing German Student Union entered Magnus Hirschfeld’s Institute of Sexual Research in Berlin.

Hirschfeld’s expansive library of sexual and gender studies was confiscated and later burned in the streets of the German capital, one of many book…