Cape Ann turkey, n. — Green’s Dictionary of Slang

Cape Ann turkey n.

also Cape Bon turkey

[SE Cape Ann, a cape in northern Massachusetts]

(US) salt cod.

1844		Knickerbocker (N.Y.) XXIV 470: My heart sank [...] I had left a real gobbler at home, to come here and dine on a ‘Cape-Ann turkey’! Of all articles tolerated [...] I most abominate boiled salt fish .
1947		R. Berolzheimer US Regional Cookbook 72: Salt Codfish (Cape Ann Turkey) [DA].
1947		Exeter & Plymouth Gaz. 24 Dec. 4/2: Codfish dubbed ‘Cape Bon turkeys’.