Green’s Dictionary of Slang

I don’t care n.

also I declare

[rhy. sl.]

(US) a chair.

1935		A.J. Pollock Und. Speaks.
1944		Maurer & Baker ‘“Aus.” Rhyming Argot’ in AS XIX:3 193: I Declare/ I Don’t Care – A chair.
1949		Monteleone Criminal Sl. (rev. edn).