Green’s Dictionary of Slang

(US) a euph. for god-damned adj.

1832		J.K. Paulding Westward Ho! I 175: I wish I may be goy blamed if he didn’t spring up higher than the top of the cane-break.
1889		Dead Bird (Sydney) 12 Oct. 7/3: I’m goin’ to paste the gol-blasted duffer’s nose all over his face inside of six rounds.
1925		Dos Passos Manhattan Transfer 25: What right have these golblamed automobiles got racin round the city knockin down wimen an children?