Green’s Dictionary of Slang

darnation n.

(US) a euph. for SE damnation, i.e. hell.

[US]J.K. Paulding Bucktails (1847) II ii: Name? Why darnation how should I know?
[US]Southern Literary Messenger VI 508/2: ‘O, darn it to darnation,’ muttered Joe [DA].
[Ire]Cork Examiner 8 Jan. 4/4: I’ll be darned to darnation if i wouldn’t have knocked that pesky varmint into a cocked hat.
[UK]Worcs. Chron. 21 Mar. 6/1: I hope I may be darned to all darnation if I wouldn’t chaw up your ugly, mummyised corpse.
[UK]Morpeth Herald 30 Mar. 3/3: The darnation ye don’t!
[Scot]Fife Herald (Scot.) 1 Feb. 4/3: Darn their ’ceitful eyes [...] blame their skins, torment their hearts, and drot them to darnation!
[UK]G.H. Nicholls Bayete! 37: Darnation tak’ yer!
[Scot]Eve. Teleg. 30 Nov. 6/3: A hazy but very pleasant voice murmered, ‘Darnation take it!’.