'The Second Coming of the KKK' explores the largely forgotten 1920s resurgence of the Klan

In the years after the Civil War, the Ku Klux Klan rose from the bitterness and racism of the South to claim the mantle of American white supremacy. We think of this era when we picture hooded men on horses who burn crosses and lynch people.

But there's another KKK that's largely forgotten today, a national phenomenon in the Roaring Twenties that transformed Klan members and their allies into mayors, governors, and U.S. senators in states from Oregon and Colorado to Indiana and Maine.

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