Green’s Dictionary of Slang

(US) extreme, thus all-firedest(see 1871, 1875).

1836		T. Haliburton Clockmaker I 261: ‘Look at that ’ere Dives,’ they say, ‘what an all-fired scrape he got into by his avarice with Lazarus.’.
1849		W.C. Hall ‘Mike Hooter’s Fight with the “Bar”’ Spirit of the Times (N.Y.) 10 Nov. 452: I hearn the all-firedest crackin’ ’mongst the cane that you ever hearn any whar.
1851		‘How Sally Hooter Got Snake-Bit’ in T.A. Burke Polly Peablossom’s Wedding 69: The fust thing she knowed he bit her, slap — the all-firedest, biggest kinder lick!
1864		J.R. Lowell Fireside Travels 185: Cappen, this ’ere ’s the allfiredest, powfullest moon ’t ever you did see.
1873		W.H. Thomes Bushrangers 15: ‘I’m ready,’ he answered; ‘but it’s an all-fired dodge, to leave home; now ain’t it?’.
1871		‘Artemus Ward’ Complete Works 464: IT IS THE ALL-FIREDEST PAPER EVER PRINTED IT'S THE CUSSEDEST BEST PAPER IN THE WORLD.
1875		Capt. Boyton in Gent’s Mag. 283 June 717: I saw Butler blow up his fire-ship. [...] It was the all-firedest clap of thunder that ever knocked at my ears.
1883		J. Keane On Blue Water 36: I heard curses deep and bitter called down upon the head of the man who invented it by some poor wet and famished sailor, as he forced a few spoonfuls of the ‘all-fired mess’ into his famished maw.
1885		Bulletin (Sydney) 19 Sept. 14/2: If I’d bin the leanest, meanest, alfiredest mongrel, with a kettle on the end of it’s a’mighty tail, I couldn’t a bin more closely followed or madly grassed.
1893		Eve. World (NY) 12 Jan. 3/5: I’m going to give you the all-firedest licking you ever got.
1900		J. Conrad Lord Jim 146: There had been no news for more than a year; they were kicking up no end of an all-fired row amongst themselves, and the river was closed.
		Truth (Brisbane) 10 Apr. 5/2: The great, all-fired son of Salvation spent Christmas and Boxing Days in the booby hatch for stouching, slanging, and other similar harmless recreations.
1906		Greenville Times (MS) 26 May 6/3: D’you know [horses]’ll eat pork? [...] though they’re an all-fired sight wuss afterwards.
1916		Broadford Courier (Brisbane) 14 Apr. 1/4: ‘All-fired’ is used as [a] general intensive, such as ‘all-fired racket’.
1916		‘Anzac’ On the Anzac Trail 72: Of course, there were little isolated pow-wows now and then, but they always ended in such an all-fired jamboree that the tenderfeet effendis [...] thought the bottom had fallen out of hell.
1925		G.H. Mullin Adventures of a Scholar Tramp 79: The all-firedest biggest bulldog I ever clapped eyes on.
1964		J. Thompson Pop. 1280 in Four Novels (1983) 439: Are you in such an all-fired hurry I can’t even [wash my hands].
1974		(con. 1945) M. Angelou Gather Together In My Name 93: You think because of your all-fired principle some of the men won’t feel like putting their white sheets on and riding over here to stir up trouble?