That man there on the left is Rep. Jonathan Cilley, a promising young Democrat from the great state of Maine. Or rather, he was a promising young Democrat, until his distinguished colleague, Rep. William Graves of Kentucky, a Whig, shot him in an 1838 duel. Like most duels, it was a little absurd; as the House website notes, "neither man had any known grievance with the other prior to the incident" (normally a deal-breaker). But Cilley had offended Graves' friend, and so Graves felt that it was only right—gentlemanly, even—to demand satisfaction on his behalf.
Never letting a good crisis go to waste, the House passed stringent anti-dueling legislation one year later in Cilley's memory, and then, in another timeless congressional tradition, totally ignored it. In 1860, six members convened for an epic 3 v. 3 gunfight in Maryland; that same year, one congressman challenged another to a battle with bowie knives.
And that was just the beginning. I dug up more than a dozen instances of our distinguished representatives in Washington beating the bipartisanship out of each other, police officers, and, occasionally, total strangers. Forget everything you've heard about how Washington is more polarized than ever before; armed confrontations are as much a part of the legislative process as backroom deals and motions to recommit. Check it out.