Well, Brewer's Dictionary of Phrase and Fable 1969 edition gives "jingoism" as deriving from that music hall song of 1878, written by GW Hunt. ("Jingo" is given as "a word from the patter and jargon of 17th century conjurors, probably substituted for "God".)

I wonder if GW Hunt might have been thinking of the Annexation song when he wrote this one.