Green’s Dictionary of Slang

joe goss n.

[rhy. sl.; ? ult. late-19C US prize-fighter Joe Goss (1837–1885)]

the boss; thus a political boss.

[US]T.A. Dorgan in Zwilling TAD Lex. (1993) 50: Joe Goss (that’s the boss.).
[US] ‘Hotel Sl.’ in AS XIV:3 Oct. 239/2: joe goss Politician.
[US]Maurer & Baker ‘“Aus.” Rhyming Argot’ in AS XIX:3.
[US]E. Bunker Mr Blue 57: You think about God – is there one or many – and why he allows so much pain and injustice if he is the Joe Goss.