Fritz Stern, a German-born historian and longtime professor at Columbia University whose searching studies of Germany’s political culture in the 19th and 20th centuries provided a new understanding of the drift toward totalitarianism, died on Wednesday at his home in Manhattan. He was 90.

The death was confirmed by his wife, Elisabeth Sifton, the former senior vice president of the publishing company Farrar, Straus & Giroux.

Like many German historians of his generation, Professor Stern sought to explain the causes behind the events that upended his own life and that of his family, Jews who lived a prosperous, assimilated life in Breslau until oppressive conditions forced them to emigrate to the United States in 1938.

“Though I lived in National Socialist Germany for only five years, that brief period saddled me with the burning question that I have spent my professional life trying to answer: Why and how did the universal potential for evil become an actuality in Germany?” he wrote in the introduction to “Five Germanys I Have Known,” a blend of memoir and history published in 2006.

In his first book, “The Politics of Cultural Despair: A Study in the Rise of the Germanic Ideology,” published in 1961, Dr. Stern shed light on the intellectual climate that made Germany receptive to Nazi ideology. He took an unusual tack, studying lesser-known figures — the cultural critic Julius Langbehn, the biblical scholar Paul de Lagarde and the man of letters Arthur Moeller van den Bruck — whose mystical nationalism and hostility to Western liberal values represented broader intellectual trends. ...