Green’s Dictionary of Slang

1. a soft felt hat with broad brim and low crown.

1844		Courier (Hobart, Tas.) 26 Apr. 2/6: One of these ruffians was dressed in a blue jacket, drab trousers, and a hat, which has obtained the somewhat slang term of ‘Jim Crow’.
1864, 1867, 1870		Hotten Sl. Dict.

2. (US black, also jim-crow card) a small card, resembling a currycomb, used by negroes in rural areas.

1887		C. Chesnutt ‘The Goophered Grapevine’ in Conjure Woman (1899) 22: He wuk at it ha’f de nigh wid er Jim Crow, en think he git it straighten’ out.
1908		L.W. Payne Jr ‘Word-List From East Alabama’ in DN III:iv 325: jim-crow card, n. A currycomb: so called because the negroes sometimes use it for combing the kinks out of their hair.