In 1927, 1,000 white-robed Klansmen rioted in Queens. Trump's father was arrested in that incident.

_____The predication for the Klan to march, according to a flier passed around Jamaica beforehand, was that “Native-born Protestant Americans” were being “assaulted by Roman Catholic police of New York City.” “Liberty and Democracy have been trampled upon,” it continued, “when native-born Protestant Americans dare to organise to protect one flag, the American flag; one school, the public school; and one language, the English language.”

It's not clear from the context what role Fred Trump played in the brawl. The news article simply notes that seven men were arrested in the “near-riot of the parade,” all of whom were represented by the same lawyers. Update: A contemporaneous article from the Daily Star notes that Trump was detained “on a charge of refusing to disperse from a parade when ordered to do so.”

When news of the old report surfaced last year, Donald Trump vehemently denied his father's arrest. “He was never arrested. He has nothing to do with this. This never happened. This is nonsense and it never happened,” he said to the Daily Mail. “This never happened. Never took place. He was never arrested, never convicted, never even charged. It's a completely false, ridiculous story. He was never there! It never happened. Never took place.”

...It's worth noting that Trump's comments came one day after another Klan brawl, this time in Anaheim, Calif. Thirteen people were arrested and three were stabbed after a Klan rally turned violent. And it's worth noting, too, as did Jonathan Chait at New York magazine, that Trump's claim to “know nothing” about white supremacists echoes the language of the 19th-century “Know Nothing” party — a nativist group that supported only Protestants for public office...