I suppose it depends on what you mean by " quite progressive"...

"Know Nothings were not content to attempt to bring about their agenda through peaceful means. Intimidation meant to keep Catholics away from the ballot box came to a head on August 6, 1855, in Louisville, Kentucky. In a hotly contested race for the office of governor of that state, Know Nothings killed 22, injured many more, and destroyed property." (From the Wikipedia entry, for convenience. But the account appears to be accurate enough.