Green’s Dictionary of Slang

a general intensifier.

1864		‘Edmund Kirke’ Down in Tennessee 162: I nuver totch the dingnation stuff.
1864		Empire (Sydney) 15 Feb. 2/2: Ye is a outdacious, dingnation, nat’ral borned fool.
1884		Anderson Intelligencer (SC) 7 Feb. 1/5: That dingnation old billy goat went and throw’d me this morning [...] confound his dingnation old hide.