Green’s Dictionary of Slang

violent, whether lit. or fig'; often as in knock-down arguments.

1807		Irving & Paulding Salmagundi (1860) 215: They [...] not being able to make each other clearly understood, resorted to what is called knock-down arguments.
1808		G. Andrewes A Stranger’s Guide or Frauds of London [frontispiece caption] He is robbed by the Prostitute he wishes to embrace—Her Bully receives her Plunder and is ready to convince him by knock-down arguments, he is in a house of—Repute.
1832		Quid 246: My head came in contact with a cocoa-nut tree. The blow loosened the fruit; one fell on my head, and convinced me, by knock-down argument, that I was awake.
1833		Albany Microscope (NY) 5 Jan. n.p.: The claret running [...] from the proboscis. Pretty considerable strong proof [...] that some knock down arguments had been used.
1850		Life in Boston & N.Y. (Boston, MA) 18 May n.p.: Being involved in a knock-down argument with another gent.
1857		Bell’s Life in Victoria (Melbourne) 30 May 2/4: [H]e had nothing but knock-down arguments for everybody.
1870		Richmond (VA) Whig 7 July n.p.: That was a clincher; I don’t know when I have heard a knock-down argument which left the opponent so little life and breath.
1902		W.N. Harben Abner Daniel 179: I would be out of the place at one of the—the knock-down and drag-out shouting-bees.
1944		R. Olds Helldiver Squadron 151: A hot exchange nearly ending in a knockdown fight ensued.
1984		(con. WW2) T. Jones Heart of Oak [ebook] Any other youngster who might have suggested that we were [prudish] would have soon found himself in a stand-up and knock-down fist-fight which would have swiftly and bloodily relieved him of his misapprehensions.